ISSUE-21: Added a basic Win32RenderWindow implementation for managing a window's lifetime.
ISSUE-21: Added a caption argument to the Win32RenderWindow constructor.
Added a make_surface to make an image_surface for use as a render target. Switched code to draw to the render target surface and then paint in one shot to the Win32 window. Removed flickering by removing CS_HREDRAW and CS_VREDRAW, which in turn required a work around for a bug of unknown provenance that was causing a crash when resizing a window. Window now does not update contents while being resized. Should fix issue #23. Code should run slightly faster and much cleaner now that it handles painting directly when there is no message rather than triggering a WM_PAINT message. Issue #26 changes are complete.
Merge remote-tracking branch 'origin/ISSUE-26' into ISSUE-21
ISSUE-21: Moved most Win32 message handling to the Win32RenderWindow class.
ISSUE-21: Cleaning up some of the commented out code.