issue #1524 - Units in Draft Gui
 - basic working version for points,radii entry
 - logic added to Trimex, Offset, Rotate
+ compile with clang
+ Better support of clang, fix issues discovered by clang
+ Fix DLL warning with MSVC
+ issue #0001419: FreeCAD crash on Windows 8.1.
+ fix flaws found with code analyzer tool
issue #1524 Add UNITS to Draft Shapestring
issue #1524 UNITS for Draft Dimension