openbor Tools

Check transparent bg for 8bit water (though it is rare).
Fix enemy stuck bug when multiple items overlap each other and some of them are not pickable, also reduce their chance to chase items.

Optimize 8 bit water.

Move sprite_map and sprite_list declaration from types.h to openbor.c

For some reason models.txt didn't skip commented lines (#....).
Fixed.

Fix CMD_MODELSTXT_MAXIDLES, should be 1 instead of 0.

Fix a hall of fame crash bug when a player model is unloaded (e.g., AOF BORR).
Fix a select screen crash bug when a player model is unloaded (e.g., AOF BORR).
Add a temporary solution that NULLs the model handle in model_cache before deleteModel is called.
TODO: merge model cache logic (model_cache and modellist should be checked at the same time).
Other minor fixes:
Change most of the bit field type to int in openbor.h, otherwise the compiler tends to complain when they are used as array subscripts without a cast.
Clear player keys after a scene (otherwise there's no way to skip a scene before a select txt without triggering a confirm button).

Removed force mprate check when magic_type = 1.
Change error message of script function loadmodel to fit the new logic.

Update uncache sprite functions.
How it allows unloading only the sprites and keeping the model.

Unload flag 2 for model, delete sprites as well.
TODO: take care of those subclassed models.

Expand s_sprite structure and chagne other sprite related stuff for later use.
Now s_sprite stores original width and height as well as offsets to avoid loading and cropping the same image file multiple times.