Prevent build script failing on prime build with fresh git clone

reason of failure was task compileHtrootServlets executing during gradle init
and javac resulting in error as not dependencies available in build dir

- happened only on very first build with with a fresh cloned repository

build.gradle

@@ -33,6 +33,14 @@ sourceSets {
             srcDirs = ['test/java']
         }
     }
+/*    
+    htroot { // optional sourceset to have htroot servelets available/visible in development IDE
+        java {
+	    srcDirs = ['htroot']
+            compileClasspath = configurations.compileClasspath + jar.outputs.files
+}
+    }
+*/
 }
 
 group = 'net.yacy'
@@ -195,22 +203,22 @@ compileJava.dependsOn(prepYaCyProperties) // must be executed before compile (du
 // implement ant task to simulate old Ant build for htroot,
 // to avoid import of complete build.xml (as currently used)
 task compileHtrootServlets (dependsOn: ['jar']) {
-
-    ant {
-        path(id:'project.class.path') {
-            // place yacycore.jar on classpath (not automatically done)
-            pathelement (location: jar.archiveFile.get())
-            // construct path elements
-            configurations.compileClasspath.each { pathelement (location: it) }
-        }
-        javac (srcdir:'htroot', excludes:'processing/**',
-            source:java.sourceCompatibility, target:java.targetCompatibility,
-            debug:"true", debuglevel:"lines,vars,source", includeantruntime:"false", encoding:"UTF-8") {
-            classpath (refid:'project.class.path')
+    if (buildDir.exists()) { // prevent buildscript failing on prime build with fresh git clone due to javac error during gradle init
+        ant {
+            path(id:'project.class.path') {
+                // place yacycore.jar on classpath (not automatically done)
+                pathelement (location: jar.archiveFile.get())
+                // construct path elements
+                configurations.compileClasspath.each { pathelement (location: it) }
+            }
+            javac (srcdir:'htroot', excludes:'processing/**',
+                source:java.sourceCompatibility, target:java.targetCompatibility,
+                debug:"true", debuglevel:"lines,vars,source", includeantruntime:"false", encoding:"UTF-8") {
+                classpath (refid:'project.class.path')
+            }
         }
     }
 }
-startScripts.dependsOn(compileHtrootServlets)
 
 // copy additional files into directory used to create distribution archive (distZip/distTar)
 task copyFilesToDistDir (dependsOn : ['compileJava', 'jar', 'compileHtrootServlets']) {  
@@ -324,8 +332,7 @@ task copyDependenciesForDistribution {
             into instDir + "lib"
         }
         copy { // add own jar (not included automatically)
-            from 'lib'
-            include 'yacycore.jar'
+            from jar.outputs.files
             into instDir + "lib"
         }
 }
@@ -381,7 +388,8 @@ tasks.withType (Javadoc) {
 
 // some legacy stuff packaged in separate archive
 // archive in build/distributions
-task packagePortalsearch {
+task packagePortalsearch (group:'distribution') {
+    description 'Bundles the javascript portalsearch as *.tar.gz distribution'
     ant {
         tar(destfile:'build/distributions/yacy-portalsearch.tar.gz', compression:'gzip', defaultexcludes:'yes', longfile:'fail') {
             tarfileset (dir:'htroot/portalsearch/', prefix:'yacy/portalsearch/') {