Merge branch 'master' of D:\Documents\GitHub\sketchup-shapes
Last code format/style tidy-up - removed brackets round a few if() statements, renamed variables to less cryptic names
Use relative paths for location-independent installs
Merge pull request #19 from jimfoltz/feat/location-independent

Use relative paths for location-independent installs
Added Helix shape, based on previous DrawHelix14.rb by Jim Foltz, in turn adapted from DrawHelix13.rb by Peter Brown 4/8/2004
Works to draw, and remembers previous parameters, but isn't editable (doesn't yet use mesh_additions.rb to draw the helix)
Still to do: use mesh_additions; allow left hand as well as right hand screw shape
Now draws in container (not model), so shape is editable with R-click. Allows negative values for pitch (helix goes down) and/or rotation (negative draws left hand helix)
Added angle at which to start drawing helix, as another editable parameter
Edited file comments in su_shapes.rb/shapes.rb and su_shapes.rb to reflect latest code changes, and added Helix shape to CHANGELOG.md
Minor change to starting default number of segments per rotation for helix - from 12 to 16 to match other circle-based shapes
Moved the Shapes module under the SketchupExtensions modules, similar to the STL project.
Update copyright and license headers to be consistent.
Removing redundant code documenting UI elements. This belongs in the README and Extension Warehouse description.
Cleaned up root RB file.
Refactored mesh additions to be a mix-in module that can extend pare Geom::PolygonMesh instance instead of modifying the whole class.
Moved the Parametrics class into the correct namespace.
Still need some cleanup of globals. And generic names for attributes.
Also fixed the name of the operations.
Improved labels for Torus options to be more accurate in their description.
Cleaned up Parametric's white space indentation.
Cleaning up Parametrics a little bit and adding comments. Still need much more.
Avoid modifying the collection we are iterating. Fixes #13.
Merge branch 'johnwmcc-master' into upstream-master

Conflicts:
	src/su_shapes.rb
Merge pull request #21 from thomthom/upstream-master

Resolved merge conflict with johnwmcc's latest pull request.