* Camerascale, shieldscale, height and spinheight are now player attributes which are set to the skin attribute on skin change, not read directly from the skin.
* P_GetPlayerHeight and P_GetPlayerSpinHeight are now macros instead of functions.
* Extra protection against switching to a locked skin.
The idea is for the layman Lua user to understand better what range of values to use for mobj types, states, sfxs, player #s etc. Additionally, mobjinfo/states/sfxinfo/hudinfo tables all now have actual bound checks when accessing/editing them. Yikes, why didn't they have any before?!
Angles now go from 0 to 0xFFFF (360 degrees == FRACUNIT) instead
of using a full UINT32. Lua only has one number type, so signedness
gets in the way of using angle_t directly. This handling of angles
matches up with how ZDoom ACS scripting and the like does it.
I also changed all the integer casts and pushes of fixed_t to
their own macro in preperation for possible future seperation.
