Implements use of copy-from for overmap edits

[DangerNoodle]

Removes swamp shack overmap special, as no difference was observed between mainline and the mod. I would assume that swamp shacks were ported into the main game from PK Reblance?

Additionally removed the override for prisons, as the only evident difference was different handling for how connection to a road was handled. Please correct me if the different handling has any change in net result, but it appears as though no difference resulted. If so, my apologies.

Likewise, overrides for hospitals, motels, hazardous waste sarcophagi, cathedrals, schools, and refugee centers have had the changes to overmaps and connections removed, but other overriding changes retained. Will undo this change if you request it, as I am uncertain what the change in connection handling is for.

For most other overriding overmap specials, implemented use of copy-from to reduce edits to only what was different, reducing the risk of desync with mainline and reducing the odds of any future mods interacting with the chances.

Handling of farms has been left unchanged for the moment as I am uncertain of desired handling. Mainline farms now have a connection to roads, whereas you make use of separate isolated farms (overriding) and the addition of farms with roads. Suggestions as to proper handling of this case would be desired.

Use of copy-from ensures pending changes to cathedrals, and prisons will not require any update to avoid desync with mainline, but farms will still be a problem in the future.

My apologies if I missed anything significant.

[pisskop]

The prison uses a customized entrance plot to control what can spawn there. I can re-add it after if the road doesn't mesh up to the entrance.

[DangerNoodle]

Ah, very well then. My apologies for not noticing that.

[pisskop]

not a big deal. it worked in my test.

other than that some of my redundant farms needed tweaking. thank you for the help.