Implements passive plugin system. The mod can now be modded.
Merge upstream changes

Conflicts:
	common/rebelkeithy/mods/metallurgy/core/MetallurgyCore.java - Resolved
Fixed Crusher item renderer
Moved csv files into asset package. Files can now be replaced by resource packs.
Changed so that the same code can be used to read csv files wherever they reside and whatever the development environment.
Improved logging for missing user supplied files.
Changed member name for consistency.
Merge remote-tracking branch 'remotes/upstream/master' into plugins
Merge remote-tracking branch 'remotes/upstream/master' into csv_files
Repackage for consistency
Added basic plugin load events
Converted MetallurgyBase submod to plugin
Converted submodules to plugins
Bugfix: incorrect registration of plugins on event bus
Bugfix: inconsistent config folder
Correct handling of mod instance
Merge pull request #84 from BlockAcquisitionConsortium/csv_files

Simplified csv processing
Merge upstream changes
Merge pull request #83 from BlockAcquisitionConsortium/plugins

Passive Add-In System