Moved hud.dm to code/datums. Updated the dme.
Fixed issues related to shotguns and their shells.
-The description "A weak beanbag shell. This one is spent. This one is spent. This one is spent. This one is spent." made by double barreled shotguns is gone, now the message is only added when the shotgun actually fires and uses the shell
-All other kind of shotguns will now add the "This one is spent." message.
-Shotguns will stop firing invisible bullets, making them less confusing.

Changed the "You break the double barreled shotgun" message to "You open the double barreled shotgun" because it was confusing, the playes (myself included) thought that they actually ruined the pretty gun.
Standardises lib_items.dm, including names and text styling.
Merge pull request #163 from Petethegoat/libitems2

Standardises lib_items.dm, including names and text styling.
Slimes will now save fingerprints, they had the flag FPRINT missing.
Injecting chemicals to a beaker, slime extract, etc. will now save your fingerprints on the target.
Fixes Pun Pun dying as 'The Pun Pun'.
I didn't even knew that you could add the empty shells to other guns, oh well.
Same fix for the rest of the projectile guns, now they won't "fire" invisible bullets.
Merge pull request #155 from Petethegoat/hudmove

Moved hud.dm to code/datums. Updated the dme.
Merge pull request #168 from Petethegoat/monkeydeath

Fixes Pun Pun dying as 'The Pun Pun'.
Merge pull request #165 from aranclanos/Fifth

Slime extracts fingerprint fixes
Merge pull request #161 from aranclanos/First

Fixed issues related to shotguns (& revolvers) and their shells.
Merge branch 'master' of https://github.com/tgstation/-tg-station