start of ug
doc improvements
doc improvements
change `` to `
improvements
minor doc impr
Merge remote-tracking branch 'upstream/master' into userguide

Conflicts:
	menpo/image/base.py
	menpo/image/masked.py
	menpo/model/modelinstance.py
	menpo/shape/pointcloud.py
	menpo/transform/homogeneous/affine.py
	menpo/transform/homogeneous/similarity.py
	menpo/transform/piecewiseaffine/base.py
Merge pull request #346 from jabooth/userguide

Improvements to the user guide, numerous docs fixes