Cleanup helper files maths.dm, time.dm, type2type.dm, add macros for bit-manipulation

`maths.dm`:
	Rewrite `Gcd(x)` to remove recursive behaviour.
	Remove `RaiseToPower(x)` and its usage from `event_manager.dm`.
	Rename `Lerp()` to `Interpolate()`.
	Add `Square(x)`, which squares a number.
	Rearrange most of the functions in the file. (trigonometric functions together, etc.)

`type2type.dm`:
	Rewrite `num2hex()` and optimise `hex2num()` for superior clarity and a 100% speed improvement.
	Correct indenting, spaces, make switches more concise.

`time.dm`:
	Remove old, slanderous commented-out function `/proc/time_stamp()`

`lists.dm`:
	Add the macros, `BITTEST(bitfield,index)`, `BITSET(...)`, `BITRESET(...)`
	  and `BITFLIP(...)` for bit-manipulation and use them where 20+ files
	  do it manually, for arguments of reader clarity and standardness.

code/WorkInProgress/computer3/computers/security.dm

@@ -543,7 +543,7 @@ What a mess.*/
 					if ("Change Criminal Status")
 						if (active2)
 							for(var/mob/living/carbon/human/H in player_list)
-								H.hud_updateflag |= 1 << WANTED_HUD
+								BITSET(H.hud_updateflag, WANTED_HUD)
 							switch(href_list["criminal2"])
 								if("none")
 									active2.fields["criminal"] = "None"
@@ -608,4 +608,4 @@ What a mess.*/
 
 /obj/machinery/computer3/secure_data/detective_computer
 	icon = 'icons/obj/computer.dmi'
-	icon_state = "messyfiles"
+	icon_state = "messyfiles"