Revert "Make simple_away and keepnick also support user modules"

This reverts commit fb62b5e7a6590461d5287f466198942e34c95ef9.
I need to test changes better...
To be proper user modules they need to store per-network state, just a
flag isn't enough.
Make autocycle network module, fix #340

As user module, it even doesn't behave very well, because of shared
state between networks.