Now Requires Vault for Permissions

Fixes some permissions error.

Allows use of DonationPoints.sign.use.* + Negating nodes.
Change Config Value to "SpecificPermissions"
Allow SpecificPermissions on /dp purchase

If enabled true, player must have donationpoints.purchase.packName to
purchase.
Improve /dp version

Now includes Bukkit Link and Author Info.
Fix DPConfirm on signs.
Ready to go

Changelog contains all commits since 1.6.1