fixes error/usage messages given by the cmd line parsing logic in wxApp;

also fixed the handling of long-only options in the usage messages


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@13058 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/cmdline.h

@@ -162,7 +162,10 @@ public:
     // parse the command line, return 0 if ok, -1 if "-h" or "--help" option
     // was encountered and the help message was given or a positive value if a
     // syntax error occured
-    int Parse();
+    //
+    // if showUsage is true, Usage() is called in case of syntax error or if
+    // help was requested
+    int Parse(bool showUsage = TRUE);
 
     // give the usage message describing all program options
     void Usage();