Add missing materials to Step. Fixes BUKKIT-4074

When Minecraft 1.4.6 was released, Nether Brick texturing to steps
was added. Minecraft 1.5 added Quartz texturing to steps. When Bukkit
was updated to these version the textures for steps were not applied.

Currently it is not possible to set the texture of steps to quartz
or nether brick. This commit fixes that by adding the respective values
to the allowable materials list.
Fix missing closing bracket in addEnchantment. Fixes BUKKIT-4126

Prior to this commit the message would display as "...(given #, bounds
are # to #". This commit changes that by adding the missing bracket to
the end of the statement. This is strictly a visual error.
Use command block's world for /gamerule. Fixes BUKKIT-3274

In vanilla, gamerules are global, across all worlds. Maps created for
vanilla that use command blocks expect this behavior, which is broken
when they are placed on a world that is not the default world (world #0).

This commit changes that by using the command block's current world when
executing the command, forcing the game rules executed to be executed in
the world the command block is currently in.
Use in-game name
Use native snakeyaml DumperOptions to format with platform linebreak
Allow arguments to be supplied with server command aliases; BUKKIT-3134
The server bukkit.yml aliases section will pass arguments supplied along
with appending arguments supplied on the command line at execution time.
Update snakeyaml to 1.12; Adds BUKKIT-48, BUKKIT-3896

http://code.google.com/p/snakeyaml/wiki/changes
Issue 66 "Provide serialization with minimum layout change" is fixed in
snakeyaml 1.11 and addresses BUKKIT-48.

This commit also introduces an improved error message when a TAB is
attempted to be used for indentation.