Complete update of headers for files, imports, etc.
- Fixed headers for all files
- Remove unused imports
- Dependency CraftBukkit changed to Bukkit
- Will now shade metrics in (derp)
- Added HEADER.txt
- Updated LICENSE.txt
- Removed .project, .classpath, .settings and infoguide.iml
Signed-off-by: Steven Downer <grinch@outlook.com>