LuaUtils_GetLocationString

[E. Wing]

I just pushed in a few enhancements.

Added FATAL_ERROR event for when LuaPublicAPIHelper.lua is not found/loaded/run
successfully.

Added LuaUtils_GetLocationString(lua_State*) which generates a string
which contains the current function, file, and line number a script is
currently at. This is meant to assist with error reporting.
It tries to generate a string like:
SomeFunction:/home/foo/MyProj/CMakeLists.lua:151

where SomeFunction is the current function the script is currently in,
and 151 is the line number.

I use the LuaUtils_GetLocationString for when the Lua-CMake API
binding gets invalid arguments.

Thanks,
Eric