xfreerdp: several fixes for panned/pinched drawing

- use bilinear filter instead of nearest filter
- fixed invalid transformation matrix
- support non-proportional scaling
- fix calculation of transformed coordinates (rounding errors)
xfreerdp: remove duplicated drawing operations

Most of xfreerdp's hw gdi callbacks did the the same X11 drawing operation
twice: Initially on the primary pixmap to keep the back buffer up to date
and then directly on the window in order to see the result.
This sequence is followed by a call to gdi_InvalidateRegion() to mark the
rectangular area of the drawing operation.
Since in xfreerdp's current design (or better current evolved state) the
backbuffer pixmap is obligatory, all drawing operations directly targeting
the window are redundant because of the subsequent EndPaint (mapped to
xf_hw_end_paint) where the damaged region is copied from the backbuffer
to the drawable.

- removed X11 drawing operations which directly target the window drawable
- fixed some errors in the calculation of the required update regions
xfreerdp: added smart sizing, mt gesture fixes

- removed setting ScalingFactor
- added settings SmartSizingWidth and SmartSizingHeight
- changed option /smart-sizing to optionally support <width>x<height>
- consolidated transformation of input event coordinates
- rdp8 gfx ignored scaling and panning offsets: fixed
- never resize window on panning/pinching
- simplified keyboard multitouch gesture debugging emulation
- disabled keyboard multitouch gesture emulation debug code via define
Merge pull request #2240 from nfedera/fix-2014-12-01-01

xfreerdp: pinch/pan fixes and smart-sizing