[crossfire] Code Doxygenification

[Nicolas Weeger (Laposte)]

Hello.

I just did all files in the common/ subdirectory :)
(fixed indent and comments)

Ok, i didn't comment *all* parameters, i did feel stupid for writing obvious 
things.

But resulting documentation looks nice ^_-

Now, I warn you: I will track and hang, after some smacking, anyone committing 
code not indented correctly, and/or without comments *evil grin*


Nicolas