Grappling Hook Mod

Fixed some bugs (thanks JeffBobbo for reporting them)
Note that this is not compatible with v1 (Don't have a client and server with different versions)

Fixed bugs (see github for more info):
stop motion on collision
ender staff/ender grappling hook force push timeout isn't global
hooks seem to want to push/pull you to whatever their length is
you can be moved by your grappling hook while in bed
right clicking blocks causes issues with the ender grappling hook
Fixed momentum building up during pause
Grappling hook removed when block is destroyed
Fixed climbing up walls when grappling hook isn't directly above player

may have fixed: 
crash report
smart moving control conflict

Also added grapplingBlocks and grapplingLength gamerules (see minecraftforum for explanation)