Merge pull request #1183 from JoeCreates/dev

Don't ever floor the origin part of sprites render position when FLX_RENDER_TILE. closes #1079, closes #1169 and possibly closes others
possible problem with caching BitmapDatas
fix for issue #1185
Revert to old rounding for flash rendering. Use getScreenXY() for rendering.
Make rendering use FlxObject#getScreenXY(). Make getScreenXY() floor object positions. Make more use of FlxPoint methods.
Merge branch 'dev' of https://github.com/HaxeFlixel/flixel into dev