MinecraftForge/FML@10b16d32da4b7c32b15e69cf1c636505ebbe2540 Use json 2.9.1 nightly for OSX in release json like vanilla does.
Remove SideOnly(Client) in IBlockAccess.isAirBlock
Re-added deprecated liquids system. To be removed next major MC versions after issues with Fluids are fixed. (reverse-merged from commit 9b5208fa308f22c24e295ce3be38dcafea2857ea)
This WILL be removed and should not be developed against aside for a temporary 1.6 release.
LivingOnLadderEvent

Using the method setLivingIsOnLadder allows an event based check for
being on a ladder. Will default to block.isLadder. Uses as per issue
#672