Add @asyncio.coroutine to a ton of plugins

Note: also updates some plugins to new format (inp -> text, multiple @hook.commands -> one hook)
Remove the option to use threaded=X or async=X, leaving only @asyncio.coroutine
A few more plugin updates
Formatting imports
Might fix sieves
Documentation updates! Tons of them!

(also merges kill.py into attacks.py)
Merge branch '3.4-mass-asyncio' into python3.4