Merge pull request #504 from Glitchfinder/master

Making it impossible to attempt to drop air
Merge pull request #505 from Glitchfinder/master

Fixing some leaderboard-related NPEs.
Allow for a chance at 3x drops from Super Breaker again - Addresses #456
To keep me from accidentally deleting this again...
Merge pull request #506 from Glitchfinder/master

Further reducing lag when saving or unloading a world.
NPEs are bad and I should feel bad.
Fixed a bug with Blast Mining incorrectly handling reduced TNT damage.
ACTUALLY fix issue with TNT damage - Fixes #510.
Fix NPE resulting from using /mcremove command on a Flatfile DB. Fixes
#509.
Fix issue where Tree Feller affected player-placed blocks. Fixes #507
Axe restructuring.
Remove unused variable.
Finish Axe restructuring, modify a little bit of Swords stuff as well.
Changelog update.
Allow configuration of Skull Splitter damage modifier.
FFS Leaderboard rewrites, and new mcrank command.
Merge branch 'master' of https://github.com/mcMMO-Dev/mcMMO
Sometimes I forget how to use git (all the time)
Tip: Shoot the cyberdemon until it's dead.
Part one of sql for mcRank