Changed /ascend and /descend to get arguments via injection.
Added support for mathematical expressions for numeric arguments in commands.

This only works for commands that have been ported over to the new command
framework.
Added //calc, //eval, etc. to evaluate mathematical expressions.
[Bukkit] Added shim method for setBlock(..., foundation.Block, ...).
Adds Platform support for WorldEdit CUI
Merge pull request #298 from DarkArc/master

Fixes WorldEdit CUI.

Closes WORLDEDIT-3150.
[Bukkit] Added runtime dependency for running Bukkit.
Restored tab completion of player names.

Fixes WORLDEDIT-3144.
Fixes //desel no longer working.

Closes WORLDEDIT-3146.
Clamp acceptable density for //flora and //forest.

Fixes WORLDEDIT-3148.
Allow masks parsed from input to ignore the blacklist.

Fixes WORLDEDIT-3149.
Fixes masks parsed from input not using block wildcards.

Closes WORLDEDIT-3147.
Merge branch 'master' into feature/mapping

Conflicts:
	src/bukkit/java/com/sk89q/worldedit/bukkit/BukkitWorld.java
	src/main/java/com/sk89q/worldedit/command/SelectionCommands.java