The great merging

After being added in the 14th commits of Pencil.js, Lerna has been retired in the 672nd one (that's 658 commits or 2 years and 5 months of service).

Modularity is, and has always been, one of the core principle at the heart of Pencil.js development. Lerna was a big helping hand for that purpose. But things changes. With now 44 individual modules, it became cumbersome to maintain and very slow to execute any actions.
That's why I made the decision to remove the use of Lerna and merge all module under the Pencil.js package. All old modules are now unmaintained. However, they should stay compatible with the new package in the foreseeable future.

Also:

• Draggable and rotatable now return a stop function
• All Input now support shadow and origin options
• Add a stop function to all events
• Minor performance improvements