Some GDraw Fixes

This fixes a few annoying bugs that I noticed -
* #1390 is fixed, thanks to a fix based on the patch from [unnoficial-fontforge-cygwin](http://www.geocities.jp/meir000/fontforge/fontforge-20140104-cygwin.patch.txt)
* Using the scroll wheel on menus works properly now. **I think this affects all platforms - could someone please confirm whether this is the case?** The problem was if you tried to scroll when in a menu, it would 'click' the item and not scroll the menu. If scrolling works fine on other platforms, then I'll have to make this change specific to Windows only.
* Resource loading was sort of broken on Windows, because the resource handler (or whatever you called it) expects "fontforge", but on Windows you get "fontforge.exe".