Add Part_RegularPolygon,

regular polygon edge in Part workbench "create primitives",

Add icons Part_Polygon and Part_Spline
rebase auto merge error fixes

Signed-off-by: jmaustpc <jmaustpc@users.sourceforge.net>
minor error hide Height PrimitiveFeature.h
rebase auto merge error fix AppPartGui.cpp

add ViewProviderRegularPolygon
minor code clean ups removing previously hidden unwanted code

PrimitiveFeature.cpp
PrimitiveFeature.h
+ Fix icons names
Draft: polygon tool can now use Part::RegularPolygon - fixes #0001305
Raytracing: small bugfix in preferences
Draft: changed Part::Polygon properties names
Arch: Better sectionplane widget
Add Attribute to FemMeshViewProvider python class to get all visible FemMesh faces.
Hull and Minkowski operations using OpenSCAD
fix property names for Part RegularPolygon and Prism

Prism properties: - Polygon, Circumradius and Height
RegularPolygon  : - Polygon and Circumradius

DraftTools updated to reflect the change in property names
Part_Prism in OpenSCAD,

update references to the properties of Part_Prism
in importCSG.py and prototype.py
fix error Part_Prism in OpenSCAD,

update references to the properties of Part_Prism
in exportCSG.py
+ allow to set custom tolerances on validate sketch tool
Draft: Fixed regular polygon default name
Merge branch 'master' of ssh://git.code.sf.net/p/free-cad/code
+ fix possible endless loop in mesh grid, allow to set an array of points to the kernel
Material: Created material editor

Materal editor is now funcional, abeit not complete. Can be used to
create and save new cards. Lauch from within FreeCAD with
import MaterialEditor; MaterialEditor.openEditor()