Game rule Backport

Backport some game rule for 1.7.10 from modern minecraft.

Now we have:

• maxSnowAccumulationHeight
• maxEntityCramming
• drowningDamage
• fallDamage
• fireDamage
• pvp
• spawnerBlocksWork
• spreadVines
• forgiveDeadPlayers
• showDeathMessages
• commandBlocksWork
• immediateRespawn
• enderPearlsVanishOnDeath
• allowEnteringNetherUsingPortals
• doWeatherCycle

For the usage, see here.
Also for the mod compatibility, now compat CreateWorldUI for the gamerule name, tooltips, and catogories