Various somewhat urgent fixes

*Fixes the gaussian PRNG
*Fixes a minor mistake in num2hex
*Fixes a bad call to num2hex which was causing data_core records to all have an ID of "000000". Fixes #583
*Rebalances dna modification to match the PRNG fixes.
*Fixes cloning computer not copying b_type to data disks

DNA modifier features:
*Probability indicators for emitter settings
*Info on last pulse operation
*Cannot operate on dead subjects
*UE/UI/SE spaced out more

Modified   code/__HELPERS/maths.dm
Modified   code/__HELPERS/type2type.dm
Modified   code/__HELPERS/unsorted.dm
Modified   code/datums/datacore.dm
Modified   code/game/dna.dm
Modified   code/game/machinery/computer/cloning.dm
Modified   code/game/machinery/computer/security.dm