Make stereo modes work again
Be aware that stereo rendering based on SoRenderManager does not allow background colors as the opengl buffers are cleared before rendering. As FreeCAD draws the background before the standart coin rendering the background gets erased again.
Prevent QPainter buffer swap
As the QGraphicsScene overlay does not work for all cards/drivers we disable the possible buffer swap of the qpainter, as this could be a potential source of the flickering. If the painter swaps buffers and we do it again the user will see first the correct picture (first swap) and then something uninitalized (second swap)
+ fix Qt help problems
Start: Set version info text color to white - fixes #1772
+ add missing header to Tools2D.h
Draft: Added DraftGeomUtils.pocket2d(shape,float)

Returns a list of wires obtained by offsetting the wires of the given
shape by the given amount (outer wire inside, inner wires outside) and
resolving intersections
Set PySide to all ambiguous QtGui and QtCore calls
Arch: Fixed axis object - fixes #1605
bugfix in unit parser

partly revert to 810fadab233afe9afbf3ee31ff352755ed7084eb
and change python string handling to "et" method
Draft: prevented possible deletion of draft wire during edit - fixes #1680
Little fixes to allow pycxx to compile with python3
Draft: Adapted Draft module for python3 compatibility - issue #995
+ fix stack overflow error
+ fix whitespaces
+ fix anti-aliasing issue
+ fix issues with force constraint
+ fix expressions
fixes #1740 quote pov-ray binary on windows

this fixes a bug introduced by 3523741e96d0b8db338f8f05f13282f90ccbbe67
it restores the double quotes for the shell and uses single quotes for the
python string.
fixes #1782 remove unused precsion parameters

from gp_Trsf::SetValues
use Icons for Refine and Increase tolerance features