* Reduce duplicate code
* Use more specific functional interfaces where available
* Fix some potential NPEs
* Remove some unnecessary/nonfunctional code
* Merge inventory listeners - no longer need to keep separate due to event availability
* Removed TODO items that probably won't ever be implemented. Good ideas, too drastic changes or too much work to maintain.
The common module was designed to prevent the internal modules depending on the core plugin. With the introduction of localization, this overcomplication became ever more exacerbated.
Probably will play around a bit more to remove freshly introduced static abuse before release.
Closes#61
