glass matc???? and recipe
added glass trap
glass trap infrastructure
CUT quality and recipe tweak
NON_STUCK flag
check for NULL
added NULL checks to the rest of the pit traps
Dirt floor for necropilis craters
Craters can spawn grass, where is no rubble, partially so it won't stand out.
Move item rotting related stuff into the item class.

Remove is_rotten member, it's not stored nor loaded.
Upon loading make spoiling but not jet rotten food active again.

Being active will allow the item to rot normally by triggering the processing of active items.
Typo and dirt under trashcans

Fixed a typo in mapgen and removed floor generated under outdoor
trashcans.
Convert it_comest::spoils to signed int and into turns, not hours.

We don't need yet another time scale. Making everything the same time scale (turns) avoids confusion.
Also making it a (signed) int avoids comparison warnings/problems.
Made items that are rotten show up in brown.

Since, in the inventory, the (rotten) tag might sometimes be obscured by the interface, I decided to add some color to the rotten items so they are easily identifiable.
Cleanup squad!

I am out of practice! Here's a much less messy implementation!
More cleanup and preparation for PR #9353

This commit is now depending on changes in PR #9353. Do not merge before that one is merged.
Fix guns that use UPS charges additionally to their own ammo.

Replaces the USE_UPS* flags in guns definitions with an explicit integer stating the number of UPS charges the gun uses.

Documentation.
More documentation.
added missing declaration
revert savegame.h