1. wxBase compiles/links again

2. wxString::reserve() (STLese for Alloc()) added
3. compilation fixes for mingw32/BC++


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@4695 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/string.h

@@ -705,6 +705,8 @@ public:
   void clear() { Empty(); }
     // returns true if the string is empty
   bool empty() const { return IsEmpty(); }
+    // inform string about planned change in size
+  void reserve(size_t size) { Alloc(size); }
 
   // lib.string.access
     // return the character at position n