Rewrite WorldEdit integration

This commit fixes WorldEdit integration, which was completely broken, as well as cleans up and updates WorldEdit integration while changing very little in the rest of the plugin.
Changes:
- Cleans up WorldEdit integration without creating a hard dependency on the plugin
- Fixes an exception that would arise in later versions (Missing LocalWorld)
- Updated WorldEdit version to latest DBO release
Should use 4 spaces in place of tabs.