Positive Z-levels(WIP)

Since I want to add a second floor to the Rivtech facility, I need to get positive Z-levels working, since a lot of the base is already there.

After diving into the code(including that huge if statement in mapgen.cpp), I *think*, I know what needs to be done to get it working.
Merge branch 'master' of https://github.com/CleverRaven/Cataclysm-DDA into positive-z-levels
Added sky terrain, sky overmap
Finished up, everything seems to work, as I want.
Added 3-D version of Motel
Added 3-D version of Office Tower(empty) thanks to acidia
Merge branch 'master' of https://github.com/CleverRaven/Cataclysm-DDA into positive-z-levels
Changed t_sky to t_open_air and changed the colours on them to make them more managable.
Fixed automap issue-apparently know up and know down are bad...
Transfered 3-D Buildings and made a mod.  Players will not be able to access new z-levels unless they use the debugger.
Reverted buildings back to their orignal settings.
Merge branch 'master' of https://github.com/CleverRaven/Cataclysm-DDA into positive-z-levels
Fixed lab and military bunker mapgen errors
Fixed motel issue, by added a second version of the motel building.
added 2fmotel.json file
Blaze's new & improved charcoal kiln!

This scraps the "sit there and watch it burn" charcoal recipe, and
replaces it with Blaze's automated load-light-and-leave-it! kiln.  I
altered the burn-time to six hours as requested in the forum thread.

http://smf.cataclysmdda.com/index.php?topic=6938.0

FWIW the lit kiln throws enough light to read by.  I'm content to leave
that in, but if it's a problem, we can dial it down.
Merge pull request #8064 from KA101/Blaze'sKiln

Blaze's new & improved charcoal kiln!
Adds community URLs to readme

As VlasovVitaly requested in #8061.

I'm not sure why all the URLs are really necessary, but I suppose it
helps if the mainpage goes down (Git and IRC are on other servers, but
main/forum/wiki all tend to die at the same time).
Merge pull request #8065 from KA101/contactinfo

Adds community URLs to readme
Merge remote-tracking branch 'dda/pr/7974' into dda-master

* dda/pr/7974:
  added 2fmotel.json file
  Fixed motel issue, by added a second version of the motel building.
  Fixed lab and military bunker mapgen errors
  Reverted buildings back to their orignal settings.
  Transfered 3-D Buildings and made a mod.  Players will not be able to access new z-levels unless they use the debugger.
  Fixed automap issue-apparently know up and know down are bad...
  Changed t_sky to t_open_air and changed the colours on them to make them more managable.
  Added 3-D version of Motel Added 3-D version of Office Tower(empty) thanks to acidia
  Finished up, everything seems to work, as I want.
  Added sky terrain, sky overmap
  Positive Z-levels(WIP)
Fix whitespace damage (mostly tabs).