Occupied anims, to not require special SHPs

ActiveAnimGarrisoned I think overwrites the normal active anim of the building and it is only one.

And it doesn't allow not adding extra frames to the SHP and just using a base (non-garrison) one

Currently, I know that occupy can only be a completely extra frame on the original art.

this brings up a series of issues:

- No way of making animated occupation (example: Waving flags), making stiff ones the only choice (unnatural looking)

- No way of using SHPs not specifically made for occupying as they will display bugged frames. (lack of flexibility)

- Needs to repeat entire building just for adding something so small as a flag or remap portion, that can only be static (inefficient)

In big buildings repeating the same huge SHP in another frame is also much more inefficient than adding some small overlay anims such as hanged banners, barbed wire, window planks, and sandbags, which furthermore can be reused in different locations for many buildings.

As such I propose OccupiedAnim flags be parsed by artmd.ini and triggered if the associated building is Occupied.

This would work like active anims.

OccupiedAnim=
ActiveAnimYSort=
OccupiedAnimZAdjust=

OccupiedAnimTwo=
...
OccupiedAnimThree=
...
OccupiedAnimFour=
...

Buildings with OccupiedAnims would NOT require extra Occupied and Occupied-damaged frames in the SHP

And, this is optional, but could make for a nice to watch transformation instead of instant:

OccupyMK=
(for a transition when the building is entered)