BUG: 1163 fix documentation

Source/cmProjectCommand.h

@@ -72,7 +72,7 @@ public:
   virtual const char* GetFullDocumentation()
     {
     return
-      "  PROJECT(projectname [C++] [C] [Java])\n"
+      "  PROJECT(projectname [CXX] [C] [Java])\n"
       "Sets the name of the project.  "
       "This creates the variables projectname_BINARY_DIR and projectname_SOURCE_DIR.  "
       "Optionally you can specify which languages your project supports.  "