Reverted resource references for combine_something, you can't use tool_image here, because on MSW that only works for .bmps'

Added dependency stuff to invalidate Choice images;
Fixed 'duplicate' in symbol editor

git-svn-id: svn://svn.code.sf.net/p/magicseteditor/code/trunk@197 0fc631ac-6414-0410-93d0-97cfa31319b6

src/gui/util.hpp

@@ -46,6 +46,8 @@ wxCursor load_resource_cursor(const String& name);
 wxIcon load_resource_icon(const String& name);
 
 /// Load an image for use in a toolbar (filename: tool/...) from a resource
+/** Note: should ONLY be used for ".bmp" images for now
+ */
 wxBitmap load_resource_tool_image(const String& name);
 
 // ----------------------------------------------------------------------------- : Platform look