qt: Update some messages after suggestions by translators

- *cannot* is more common, thus preferred to *can not*
- Use *Watch-only* instead of *Watchonly* as one word

src/qt/forms/overviewpage.ui

@@ -89,7 +89,7 @@
                  </font>
                 </property>
                 <property name="text">
-                 <string>Watchonly:</string>
+                 <string>Watch-only:</string>
                 </property>
                 <property name="alignment">
                  <set>Qt::AlignCenter</set>

src/qt/intro.cpp

@@ -182,7 +182,7 @@ void Intro::pickDataDirectory()
                 break;
             } catch(fs::filesystem_error &e) {
                 QMessageBox::critical(0, tr("Bitcoin"),
-                    tr("Error: Specified data directory \"%1\" can not be created.").arg(dataDir));
+                    tr("Error: Specified data directory \"%1\" cannot be created.").arg(dataDir));
                 /* fall through, back to choosing screen */
             }
         }

src/qt/locale/bitcoin_en.ts

@@ -1164,8 +1164,8 @@ Address: %4
     </message>
     <message>
         <location line="+1"/>
-        <source>Error: Specified data directory &quot;%1&quot; can not be created.</source>
-        <translation type="unfinished">Error: Specified data directory &quot;%1&quot; can not be created.</translation>
+        <source>Error: Specified data directory &quot;%1&quot; cannot be created.</source>
+        <translation type="unfinished"></translation>
     </message>
     <message>
         <location line="+24"/>
@@ -1501,7 +1501,7 @@ Address: %4
     </message>
     <message>
         <location line="+33"/>
-        <source>Watchonly:</source>
+        <source>Watch-only:</source>
         <translation type="unfinished"></translation>
     </message>
     <message>
@@ -1599,17 +1599,7 @@ Address: %4
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location line="+8"/>
-        <source>URI can not be parsed! This can be caused by an invalid Bitcoin address or malformed URI parameters.</source>
-        <translation type="unfinished">URI can not be parsed! This can be caused by an invalid Bitcoin address or malformed URI parameters.</translation>
-    </message>
-    <message>
-        <location line="+14"/>
-        <source>Payment request file can not be read! This can be caused by an invalid payment request file.</source>
-        <translation type="unfinished"></translation>
-    </message>
-    <message>
-        <location line="+62"/>
+        <location line="+84"/>
         <location line="+9"/>
         <location line="+32"/>
         <source>Payment request rejected</source>
@@ -1636,12 +1626,7 @@ Address: %4
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location line="+113"/>
-        <source>Payment request can not be parsed!</source>
-        <translation type="unfinished"></translation>
-    </message>
-    <message>
-        <location line="-366"/>
+        <location line="-253"/>
         <location line="+219"/>
         <location line="+34"/>
         <location line="+98"/>
@@ -1661,12 +1646,22 @@ Address: %4
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location line="+34"/>
+        <location line="+21"/>
+        <source>URI cannot be parsed! This can be caused by an invalid Bitcoin address or malformed URI parameters.</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location line="+13"/>
         <source>Payment request file handling</source>
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location line="+105"/>
+        <location line="+1"/>
+        <source>Payment request file cannot be read! This can be caused by an invalid payment request file.</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location line="+104"/>
         <source>Unverified payment requests to custom payment scripts are unsupported.</source>
         <translation type="unfinished"></translation>
     </message>
@@ -1681,7 +1676,12 @@ Address: %4
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location line="+33"/>
+        <location line="+20"/>
+        <source>Payment request cannot be parsed!</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location line="+13"/>
         <source>Bad response from server %1</source>
         <translation type="unfinished"></translation>
     </message>

src/qt/paymentserver.cpp

@@ -424,7 +424,7 @@ void PaymentServer::handleURIOrFile(const QString& s)
             }
             else
                 emit message(tr("URI handling"),
-                    tr("URI can not be parsed! This can be caused by an invalid Bitcoin address or malformed URI parameters."),
+                    tr("URI cannot be parsed! This can be caused by an invalid Bitcoin address or malformed URI parameters."),
                     CClientUIInterface::ICON_WARNING);
 
             return;
@@ -438,7 +438,7 @@ void PaymentServer::handleURIOrFile(const QString& s)
         if (!readPaymentRequest(s, request))
         {
             emit message(tr("Payment request file handling"),
-                tr("Payment request file can not be read! This can be caused by an invalid payment request file."),
+                tr("Payment request file cannot be read! This can be caused by an invalid payment request file."),
                 CClientUIInterface::ICON_WARNING);
         }
         else if (processPaymentRequest(request, recipient))
@@ -663,7 +663,7 @@ void PaymentServer::netRequestFinished(QNetworkReply* reply)
         {
             qWarning() << "PaymentServer::netRequestFinished : Error parsing payment request";
             emit message(tr("Payment request error"),
-                tr("Payment request can not be parsed!"),
+                tr("Payment request cannot be parsed!"),
                 CClientUIInterface::MSG_ERROR);
         }
         else if (processPaymentRequest(request, recipient))