2. reorganized wxImageList a bit, created a new wxInvertMask() function
3. an incredibly ugly fix (?) for "unsatisfied constraints" warnings
4. added wxIcon and wxBitmap ctors from XPM
5. XPM handler now creates bitmaps with mask
6. added wxPrinterDC::BitBlt() and DrawBitmap(), cleared the horrible mess in
the wxDC methods with the same names
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@5571 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775