Revert "Arch: Turned jreinhardt's fix to webGL into an option"

This reverts commit 90f2fc203466dbbb81ad26849eb3dd4b7b53f326.

Conflicts:
	src/Mod/Arch/Arch_rc.py
	src/Mod/Arch/Resources/ui/archprefs-import.ui
Use new curve discretization
Draft: Fixed wrong preferences text
fixes #0001684: Sweep ignores the list of subshapes
Draft - Allow to export Drawing pages to DXF - fixes #1686

* Uses DXF algos of the Drawing module instead of the Draft dxf library
* Uses a DXF template with the same name as the SVG template, if existing
* Only Draft, Arch, Part and Annotation views are currently supported
* Drawing module's projectToDXF() now returns only a fragment instead of a full DXF file
+ code cleanup
+ fixes #0001690: sketch.getPoint crashes FreeCAD if the point does not exist
+ fixes #0001689: Show name of the drawing page in the tab of the drawing
Arch: fix in new ifc-importer
Draft: Fixed small regression in Draft2Sketch
+ prepare property editor for items with unknown number of children
Draft: Objects drawn on an existing face will no longer take it as support unless the face was already selected
Enhanced a bit the document icon in tree view
+ improve OCC version macro, fix build failure with MinGW, fix build failure with Coin2
flush stdout after reseting the console color
+ fixes #0001696: Quantity.getValueAs('rad') touches the Property
+ fixes #0001689: Show name of the drawing page in the tab of the drawing
Reverse the projection direction of DXF exports
bugfix in Draft.ViewProiderPoint

remove access to nonexistant property
improvements to exportDRAWEXE

load only MODELING module instead of ALL
show TypeId of unsupported Objects
use angel of revolution for cones
improve sweep output
support for point, vertex, Part and Draft Polygon
cache object names to reuse them in DRAWEXE
do not expode spine which are allready edges
don't try to make faces from arcs (if this failed in FreeCAD allready)

use rounded floats if they safe digits

Sometimes the floats seems to be rounded to twelve decimal
places. we round them if it allows so safe digigts.
round angles