Added two commands

Hi Tux!  I added two straightforward commands I use myself in managing my server:  SetBlockBank, which allows you to set how many accrued blocks a player has (useful when you need to distinguish bonus blocks for any reason) and ResetClaim, which returns a user to "like-new" state with no active claims and as many accrued blocks as they initially started with as per the config.yml.  It was a simple change, but as it might be useful to others, I'll let you decide if you'd like to include it in the main line.

Thanks a bunch!  You can reach me here or on bukkitdev as MKindy.