Remove cidfile creation, sanity checks on docker, reduce cmd delay

 - No more cidfiles littering /tmp
 - We've had people confused by why the command was hanging when actually the password hadn't been set in the config. To aid in this is a) tries --version b) tries info. If one of these don't work we report a helpful error message, if they do we know we have connection to a docker daemon.
 - Pexpect has a built-in delaybeforesend option. Use this so the delays apply to every command (including checks like files existing etc). I also reduced the delay a little (now that the delay applies to every command) to stop builds grinding to an unbearable slowdown - I figure shutit seems to be stable enough at the moment to take the risk. As a result, builds appear to be faster.