Prevent npcs picking up liquids.
Fixes styles window list. (And various other windows.
code removal.
Adds wrapper for itype and it_comest and fixes lua inheritance.

Lua inheritance was seriously broken, fixed.

Check out the sample mod to see how the new itype wrapper can be used to selectively modify properties of an item from lua.
Added further wrappers for it_gun, it_gunmod and it_tool.
Merge lua improvements, NPC liquid pickup prevention, and auto hotkey assignment fix.
Nuke some dead code.