Add fps limiter for background window.
Background fps limit should not be 0 (possible div by 0).
only look at event button for button events
Option to enable 1:1.2 pixel aspect ratio
Merge remote-tracking branch 'upstream/master'
Don't alter the "Days/Hours Left" display when selling items
fix xp thing
define UFO fuel in ruleset

because USOs use Zrbite
some TFTD infrastructure

slightly more dynamic loading of graphics, function for loading palettes from lbm files

horrendous hard coding in place here, disassociating surface names from file names

sprite recolouring disabled for aquanauts for the time being.
add depth to battlescape

please note: TFTD is still not supported.
display infinity for days left with infinite # of units produced
tanks only base defense woo
fix a one in a million AI bug
Added a category filter to new manufacturing jobs.
TextList.clearList() now also resets scroll position.
Put the possble production updates back in for every new job.
Added translation strings
Blank lines are cool!
Readjust position of category filter
Nudged everything down 8 pixels, 'cuz SupSuper said so.
14 + 8 = 22