made -gamemode better, add Cobble Fence Post

in gamemode 0, starts off in inventory with 1 full stack of a lot of
block types, also, Cobble Fence Post in game inventory..
damage adjust, and can only fly in gamemode 0
Split commandline arguments into groups
Merge commit '79d4779cb6fdffb016eca76077a35c3b4485f374'

Conflicts:
	main.py
Bug fix.
Merge branch 'master' of git://github.com/avelanarius/Minecraft

Conflicts:
	main.py
Merge branch 'master' of git://github.com/avelanarius/Minecraft
Added sight and attack range properties to Entities. Player's attack range defaults to 4 (as in MC). We will probably use sight_range for mobs aggro?
Optimize world.py using Cython.
Merge branch 'master' of git://github.com/BertrandBordage/Minecraft into gui-experimental

Conflicts:
	main.py