Implement SSatoms

* Moves proc/initialize() from being on /atom/movable, /are and /turf/simulated to being on /atom - Now turfs can initialize too
* Added the SSatoms subsystem which controls initialization of atoms at roundstart and during normal conditions.
* Disabled the old auto_init = 0 behavior, ALL atoms should get initialized() called on them now.
* Refactored the way initialize() is called during /New() to utilize SSatoms instead of SScreation
* Removed SScreation, as it was only a stop-gap until SSatoms could be ported.
* Updated the maploader to inform SSatoms when it is loading maps instead of SScreation.
* Updated the template map loader to use SSatoms to perform initTemplateBounds
* Renamed 'initialized' var in seed_storage to deconflict.
* Removed usage of auto_init = 0, replaced with a no-op initialize() proc for atoms that don't need initialization.

code/modules/hydroponics/seed_storage.dm

@@ -27,7 +27,7 @@
 	use_power = 1
 	idle_power_usage = 100
 
-	var/initialized = 0 // Map-placed ones break if seeds are loaded right at the start of the round, so we do it on the first interaction
+	var/seeds_initialized = 0 // Map-placed ones break if seeds are loaded right at the start of the round, so we do it on the first interaction
 	var/list/datum/seed_pile/piles = list()
 	var/list/starting_seeds = list()
 	var/list/scanner = list() // What properties we can view
@@ -135,7 +135,7 @@
 	if (..())
 		return
 
-	if (!initialized)
+	if (!seeds_initialized)
 		for(var/typepath in starting_seeds)
 			var/amount = starting_seeds[typepath]
 			if(isnull(amount)) amount = 1
@@ -143,7 +143,7 @@
 			for (var/i = 1 to amount)
 				var/O = new typepath
 				add(O)
-		initialized = 1
+		seeds_initialized = 1
 
 	var/dat = "<center><h1>Seed storage contents</h1></center>"
 	if (piles.len == 0)