Fix for various mob attack message (take two)

* span classes instead of \red and \blue
* Making sure every attack messages from animal, slime, monkey, human and aliens are bold red for the victim and red for the other viewers.
* Replace "for(var/mob/O in viewers(src, null)) + show_message" stuff by visible_message() proc.
* Blob attack message for the target is now bold red. Blob attack message also shown for monkey target.
* Fixes #1344