Auto equip flares on night missions

Uses a spare shoulder slot.  Flares are equipped if it is sufficiently
dark, i.e. when visibility would drop to 9 tiles for XCom units, and not
equipped otherwise

Eliminates some of the micromanagement of flares.
fix negative numbers
Compiler fix
Merge pull request #703 from redv/fix_unbreack_spaces

Fix: Negative numbers.
small optimizations in tileEngine

these functions get called a lot by the drawing code and can use some minor
optimizations like this

- voxelCheck returns -1 without processing if the tile in question is empty.
- castedShade moves to the lowest logical level before checking voxels
- removes extranneous LOF trace in reaction fire checks
Optimize map draw somewhat
pop some un-needed states in new battle mode
fix battlescape timers

the timers start before the inventory state is pushed, and frameskip freaks
out because of all the time it missed, starting the timers in the init
function sets their start time more accurately.
change how fire speed works

this si a big one folks, it'll invalidate your old fire speed settings,
make sure you re-set your fire speed in the menus, or expect projectiles
to move at an undesired speed.
guarantee that no dying or fainting units try to react.
modding fix

be real picky about what file types we'll even consider loading as sprites
Added soldier memorial.
Minor fixes
fix checking for areas inside land
add third debug display to geoscape

toggles mission zone display
fix alien mission zones.
Grumble grumble makefiles
safe game saving
Sigh
Found out what should actually be the location.

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