Squashed commit of the following:

commit 6e78052d325eadcb212a6d50c6cd09cc29ac7870
Author: Johan K <johankristensen@gmail.com>
Date:   Tue Jul 29 14:52:08 2014 +0200

    Adding missing file RegularPolygon.py

commit 416396283032a31a1ea307df23d33ecfccf37935
Author: Johan K <johankristensen@gmail.com>
Date:   Mon Jul 28 22:51:28 2014 +0200

    Replaced sketcher implementation of RegularPolygons with a Python script version.
+ Add class CoordinateSystem and use it to compute placement of plane from fit
Draft + Arch: fixes when working without the GUI
Squashed commit of the following:

commit 8853bf442b6e1a98699fa90fca5eb30b3f6d3a5e
Author: Ian Rees <ian.rees@gmail.com>
Date:   Tue Jul 29 15:46:59 2014 +1200

    Refactoring and small fix in constraint icon bounding boxes

commit c03e4c13d8fd657e18e3c78d16bbdef209f8c779
Author: Ian Rees <ian.rees@gmail.com>
Date:   Mon Jul 28 15:41:15 2014 +1200

    Implemented picking of individual constraints from combined icons

commit 254aaab450fe6646bee7542c532c454af91b6597
Author: Ian Rees <ian.rees@gmail.com>
Date:   Mon Jul 28 13:04:18 2014 +1200

    Added bounding boxes for combined constraint icons

commit 4f0738ec30220fbf1abdea14dd121d0a134e5dfd
Author: Ian Rees <ian.rees@gmail.com>
Date:   Sat Jul 26 18:53:33 2014 +1200

    Added screenCoordsOfPath() to View3DInventorViewer

commit 14e2dc7b4aa79db97cbacd2c848728a66276d644
Author: Ian Rees <ian.rees@gmail.com>
Date:   Sun Jul 20 14:24:27 2014 +1200

    Bit of code to make constraint icon text rendering nicer.

    This won't be useful unless the font changes, but wanted to add it while
    I was thinking about it.

commit 8020d2d62214d71875cbae101d5ac5e96d998201
Author: Ian Rees <ian.rees@gmail.com>
Date:   Sun Jul 20 13:54:51 2014 +1200

    Fixed an off-by-one in ViewProviderSketch::combineConstratintIcons

    Bug resulted in icons occasionally not being combined into groups,
    when they should've been.

commit 20d92a3ccc1f795be1cb86f6f92045518dc8eb81
Author: Ian Rees <ian.rees@gmail.com>
Date:   Tue Jul 15 19:38:20 2014 +1200

    Fixed a bug that was introduced two commits ago.

commit 69e1ea848e3bc3c8c372c539f30a7b4d2a563aa2
Author: Ian Rees <ian.rees@gmail.com>
Date:   Tue Jul 15 15:33:30 2014 +1200

    Fixed dumb copy-and-paste error

commit a998b75a905cc31e1f4f49869e81ecaef5858b69
Author: Ian Rees <ian.rees@gmail.com>
Date:   Sun Jul 13 18:39:22 2014 +1200

    Fixed crash reported by sponssi

    More info at http://forum.freecadweb.org/viewtopic.php?f=10&t=6965&p=56590

commit 27b7b804790dda5164c7ef0b9418f6c160228859
Author: Ian Rees <ian.rees@gmail.com>
Date:   Thu Jul 10 13:32:16 2014 +1200

    Cleaning up my git repo for FreeCAD.

    This branch now has just the Sketcher icon fixes, plus a few random comment edits.
+ fix author notes, fix memory leak, fix build failure under Windows
+ Allow to get clean copy of a shape from Python
0001638: Not possible to draw anything.
Draft: diverted current dxfLibrary download folder
More detailed error message when xerces fails to read in parameters
+ Replace InputField with QuantitySpinBox
Draft: DXF lib is now pulled from its specific branch
Revert "remove TKAdvTools"

This reverts commit 6843d6ad5dc875ad0599993ac35c1852d1c97a90.
+ fix author note, fix various crashes, improve mesh selection stuff
Arch: Introduced new IFC importer/exporter

* The new IFC importer uses excusively the newest ifcopenshell.py module
* Renamed old importer to importIFClegacy.py
* Included the now deprecated ifcReader and ifcWriter modules into importIFClegacy
* The new IFC importer falls back on the older one if the ifcopenshell module is not found
Draft: Array objects now have an IntervalAxis property to build helicoidal compounds
Arch: fixed bug in wall extrusions
Arch: removed obsolete IFC preference options
Arch: Added scaling in IFC importer
Removed some debugging stuff that was accidentally pushed earlier
+ fix bug when releasing button after dragging point or curve