Lower maximum size for free transaction creation

Changes the maximum size of a free transaction that will be created
from 10,000 bytes to 1,000 bytes.

The idea behind this change is to make the free transaction area
available to a greater number of people; with the default 27K-per-block,
just three very-large very-high-priority transactions could fill the space.

src/main.cpp

@@ -753,10 +753,11 @@ int64 GetMinFee(const CTransaction& tx, bool fAllowFree, enum GetMinFee_mode mod
     {
         // There is a free transaction area in blocks created by most miners,
         // * If we are relaying we allow transactions up to DEFAULT_BLOCK_PRIORITY_SIZE - 1000
-        //   to be considered to fall into this category
-        // * If we are creating a transaction we allow transactions up to DEFAULT_BLOCK_PRIORITY_SIZE - 17000
-        //   (= 10000) to be considered safe and assume they can likely make it into this section
-        if (nBytes < (mode == GMF_SEND ? (DEFAULT_BLOCK_PRIORITY_SIZE - 17000) : (DEFAULT_BLOCK_PRIORITY_SIZE - 1000)))
+        //   to be considered to fall into this category. We don't want to encourage sending
+        //   multiple transactions instead of one big transaction to avoid fees.
+        // * If we are creating a transaction we allow transactions up to 1,000 bytes
+        //   to be considered safe and assume they can likely make it into this section.
+        if (nBytes < (mode == GMF_SEND ? 1000 : (DEFAULT_BLOCK_PRIORITY_SIZE - 1000)))
             nMinFee = 0;
     }