[SharpDX] BREAKING CHANGES: Rectangle/F Left and Top affect rectangle size

This change makes Left and Top behave similar to Right and Bottom. They
change only one edge's position which means that rectangle size changes.

Previously, Left and Top behaved identically to X and Y. They changed the
location of the rectangle while maintaining rectangle size.

This change gives users the option to adjust any single edge of the
rectangle independently or move the whole rectangle using X and Y.
[SharpDX] Clean up Rectangle and RectangleF
Merge branch 'master_integration' of https://github.com/shoelzer/SharpDX into pr153