Mostly chat-related improvements, mainly adding chattags (icons) to important channels

Also doing some cleanups and other minor changes. Read the commits, they are detailed.

Stuff changed includes:
* Chat tags, chat tags everywhere
* New ready button
* Better main menu size
* Adminhelps can now be typed in 'console' and have a confirmation
* Radio color changes
* Moved a lot of formatting stuff to stylesheet and generally cleaned up the chat output code, trying to have a unified format for messages
* Analyze-air additionaly shows temperature in Kelvin
* Posibrain asks twice if you want to join, in case you are typing and confirm the first window by pressing space or enter.
* Dead chat announcements if someone joins it or leaves, and basically a dead chat say code rewrite. It all uses one (arguably messy) proc instead of many lines of similar (definetly messy) code.
* Admins can now JMP to dead chat, ghosts can follow other ghosts, and it works both for say and emotes (because they use the same code now).
* Everyone can see player names (keys) in dead chat in addition to character names, because dead chat is mostly OOC anyway and changing names (and stuff like maintenance drone (945) and diona nymph (352) doesn't really help).
* Player is [notified](http://i.imgur.com/J4zLMZa.png) if there is some obvious mistake in their *say* message. Typing *say msay players are idiots* should be now possible only when the mod in question is an idiot, too ;)

You can see most of the stuff in [this image](https://i.imgur.com/pmkiYfd.png).

What I planned to do and didn't do: cool icons for adminhelp. Sorry, I'm sick of icons for today.
Those are static images, pre-rendered by definition. The proc just gives me a nice <img> tag to work with. Doing any rendering on server unnecessarily puts load on the server, and it's impossible to do client-side, because the chat box doesn't support it.