remove GetBoolArg() fDefault parameter defaulting to false

- explicitly set the default of all GetBoolArg() calls
- rework getarg_test.cpp and util_tests.cpp to cover this change
- some indentation fixes
- move macdockiconhandler.h include in bitcoin.cpp to the "our headers"
  section

src/main.cpp

@@ -2931,7 +2931,7 @@ string GetWarnings(string strFor)
     string strStatusBar;
     string strRPC;
 
-    if (GetBoolArg("-testsafemode"))
+    if (GetBoolArg("-testsafemode", false))
         strRPC = "test";
 
     if (!CLIENT_VERSION_IS_RELEASE)
@@ -4175,7 +4175,7 @@ CBlockTemplate* CreateNewBlock(CReserveKey& reservekey)
         // Priority order to process transactions
         list<COrphan> vOrphan; // list memory doesn't move
         map<uint256, vector<COrphan*> > mapDependers;
-        bool fPrintPriority = GetBoolArg("-printpriority");
+        bool fPrintPriority = GetBoolArg("-printpriority", false);
 
         // This vector will be sorted into a priority queue:
         vector<TxPriority> vecPriority;