Major optimization of code

Remove unnecessary permission removing in onEnable
Remove duplicated method playerRemoveOffline
Remove unnecessary try/catch in	some places of code
Register only one instance of Commands
Make loading permissions on join/leave async to avoid lag
Add Eclipse files to .gitignore

Signed-off-by: Co0sh <coosheck@gmail.com>
Merge pull request #1 from Co0sh/master

Major optimization of code