Lua: Various improvements

Some stuff requested by R00Kie.
It is correct. If you expose a function that takes a pointer as the first parameter, Luabind will treat it as if it was a member function of that class, so in this case it makes the exposed Lua function `bool CFFPlayer::IsFlashlightOn()` rather than `int CFFPlayer::IsFlashlightOn()`. When the int version was exposed, it would return a Lua number type (0 or 1) rather than a Lua boolean type (true or false).