Fixes secbot hunting, stunning and arresting maintenance drones that attack them. Secbot won't hunt them anymore, just like with silicons. Fix is done by adding a assess_threat() proc in simple_animal/drone that returns -10 (similar to silicons)
Fixes a runtime with flashes when they burn out without user, now they'll display the burn out message from the src instead.
Fixes some problems with the mime outfit sprites and changes the sprites for the bowler hat, money bag and unmined uranium.
Changes many span classes.

Replaces for(mob in oviewers) show_message()  with visible_message() when possible.

Fixes the absolute pathing in Ninja code.

Fixes facehugger attack messages being bold red for third party (only the first leap message will stay bold red for third party, for better visibility)

Standardizes vomiting message

Fixes mech occupant not receiving any attack messages when the mech is attacked.
Merge pull request #5306 from Aranclanos/flashruntime

Flashes runtime fix
Merge pull request #5300 from phil235/DroneArrestFix

Fix for #5281
Merge pull request #5311 from TZK13/Minor-Sprite-Changes

Sprite changes for the mime outfit, bowler hat, money bag and unmined uranium
Merge pull request #5318 from phil235/MsgFix2

More messages fixed
Merge branch 'master' of https://github.com/tgstation/-tg-station into prisonjumpsuit

Conflicts:
	icons/mob/uniform.dmi