BUKKIT-1567, BUKKIT-3069 fixes
* fixed WALL_SIGN directions
* fixed LEVER directions
* fixed gate creation direction
* fixed BlockFace directions
* fixed 10 layer STARGATE_MATERIAL limitation (now we check all layer)
* added two new debug commands to fix old gates
* execute "wxt fixgate <gateName>" or "wxt fixgates" to fix all existing gates
* wxt fixgate command is limited to Ops
* all changes to gate are now persistent (owner can be changed via command now)