Adjacent didn't work, back to using get_dist.
Fix #388: Incorrect C4 timing checks.

Conflicts:
	code/game/objects/items/weapons/explosives.dm
Fix #384 (possibly): Welding a fridge/freezer does nothing.
Fix for #383 - C4 deleting fridges full of corpses.
Fix for #382 - Bombs not deleting themselves and the fridge they're in.

Conflicts:
	code/game/objects/structures/crates_lockers/closets/secure/freezer.dm
Fix #384 - Fridges can be opened while welded shut.  Also discovered this extended to secure lockers.

Conflicts:
	code/game/objects/structures/crates_lockers/closets/secure/secure_closets.dm
	html/changelog.html
Fix #381 - Poster duping