Fix WorldEdit integration

LocalWorld, a class that isn't needed, was removed in 6.0.0. This broke Multiverse-Portals' WorldEdit integration and made creating new portals impossible. This commit fixes this problem by just using the regular Bukkit world. The WorldEdit version is also updated to the latest DBO release version.
Fairly sure this is going to cause a hard dependency on WorldEdit.  That's why that comment is on line 167.