[MERGED PR] Door health nerf

[Brixx79]

way beyond the pr scope and something that a coder nerd would have to handle, but i think a good middle ground could be that doors overall have their current health, but when they get down to ~1/2 or 1/3 health they enter a broken, half-open state where they can be freely entered (think the broken waste disposals door in cog 1). They still exist, so they could be given repairs and returned to an operating state.

Would mean that permanently deleting a door would still either take a ton of time or a lot of firepower, as per the current methods, but allow a focused, uninterrupted effort to maybe eventually break past a door.

I like the idea of this.  Doors aren't completely destroyed, saving the problem of replacing them.  You still need to do a good bashing to get in, but your efforts can still be repaired.  This would also fix the nukie breaching charges being useless vs doors and give them a chance of breaking them open (then getting fixed to help with defense).