Cleaned up optional lua functionality for debugging.

* Basic lua initialization
* Customized lua bindings generator with bindings for player, monster, item, uimenu and more
* Wrapper function for iuse so that if lua is enabled, lua functions can be called as well as C++ functions
* Debug option to call arbitrary lua code interactively
Added documentation for working with the lua framework.
Use pkg-config to find lua.
Made generating catalua/catabindings.cpp a build step.
Added lua linking for windows(untested but should work).
Added all kinds of *.pc names for lua5.1

Dammit, distros, get it together already!
Added missing data/main.lua

It's been sitting here all this time and I never noticed it wasn't checked into git.
Functional way to write all the .pc alternatives
Fixes recipe category for metal rail ammo.
Added ducks. Also added river spawns from GROUP_RIVER.
Added "WATCH" flag to PDA.
Merge item flag fixes.
Adds lawn darts.
suppress-chdir-warning
suppress-system-warning
fix-indentation
message fastfix
Debug menu short-range teleports no longer cause teleglow.
Long-range teleports clear the vehicle cache.
Finish removing references to snares.