new projects added

[Luiz Henrique de Figueiredo <lhf@...>]

Gaia: An Operating System for Pervasive Computing Systems 
http://www.lua.org/uses.html#173

Necro3D Game Development SDK 
http://www.lua.org/uses.html#174

gameCore
http://www.lua.org/uses.html#175

LuaBREW
http://www.lua.org/uses.html#176