Increment version, cleanup and changelog for release 2.1.0

This patch provides new changelog notes for the next release. It also does some
cleanup:

* Move CHANGELOG.md to Changelog so it gets rendered in the forge
* Fix LICENSE so only the necessary boiler plate gets displayed in the Forge

And finally it increments the Modulefile version to 2.1.0.

Signed-off-by: Ken Barber <ken@bob.sh>
Merge pull request #123 from kbarber/ticket/master/release_210

Increment version, cleanup and changelog for release 2.1.0
Fix module file, remove extra README.md and fix some docs

The module file had the wrong revision in it for starters. And there was some
missing items from the .gitignore.

The extra README.md in spec/system was getting extracted as the main README
on the forge so I remove it, moving the content that was not duplicated
already into README.md.

I took the opportunity also to finish the documentation in the Reference
section of the README to make sure all classes and defined resources are
documented.

Signed-off-by: Ken Barber <ken@bob.sh>
Merge branch 'maint/changes_before_210_release'

* maint/changes_before_210_release:
  Fix module file, remove extra README.md and fix some docs