debian build
default mode of fullscreen
added a default asset path for linux systems (although it'll incorrectly hit OSX and so forth as well), made the default campaign load through mount_campaign_package, which fixes an issue with the campaign not being mounted, made open_read_file search multiple places for the file
start with fullscreen right away, so that the screen is properly blacked out
more changes to debian rules
Cleaned up some dead code.

Added explicit destruction of the renderer, which might affect issue #4.  Destroying the window, however, messed up the rest of my desktop windows under Win7.  Other than that, it's probably an SDL bug.

Added fix for issue #5 so new SaveData always starts with 5000 gold.
Added living order check in get_num_foes().  By not counting enemy weapons (like cleric sparkles), this should fix issue #7.
Added optimization to short circuit pathfinding if there are too many walkers (> 200) in the level.  Note: this uses obmap::size(), which counts dead things too.
Added boundary check for terrain editing so there's no more array wraparound.  Fixes issue #9.
Changed fullscreen mode to SDL_WINDOW_FULLSCREEN_DESKTOP.
Merge branch 'desktop_release'