Plugins

The Drawable class has been successfully changed and the undo/redo functionality is in place. The next step is to create an interface for Jig plugins.

Before I work on creating the interface, I'm going to layout the use case for each plugin that I'll be developing. These Plugins are:
1. POAP plugin
2. M.O.S.A.I.C. plugin (this is a plugin based n my senior project)
3. POAP/M.O.S.A.I.C. plugin

The idea is to somewhat create the plugin interface from what I need instead of creating a plugin interface and trying to fit my needs into that package.

Also, I'll add the design changes that Donsi and I talked about which he also wrote comments about.