Fix scp and ssh'ing to localhost.

Fixes a bug that can occur on performing a restart whereby, with tasks running on localhost and strict ssh checking, you can end up with the situation below by removing the need to scp and ssh to localhost.

```
2013/07/31 16:36:45 CRITICAL - Suite starting at 2013-07-31 16:36:45.793344
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!

Someone could be eavesdropping on you right now (man-in-the-middle attack)!

It is also possible that the RSA host key has just been changed.

The fingerprint for the RSA key sent by the remote host is
30:c2:4f:52:80:78:fc:86:1f:42:53:f6:89:c1:06:5e.

Please contact your system administrator.

Add correct host key in user/.ssh/known_hosts to get rid of this message.

Offending key in user/.ssh/known_hosts:7

RSA host key for localhost has changed and you have requested strict checking.

Host key verification failed.

Traceback (most recent call last):
  File "user/cylc/lib/cylc/run.py", line 74, in main
    server.configure()
  File "user/cylc/lib/cylc/scheduler.py", line 351, in configure
    raise Exception("ERROR: " + str(cmd))
Exception: ERROR: ['ssh', '-oBatchMode=yes', 'user@localhost', 'mkdir', '-p', 'user/cylc-run/mot-aa850']
ERROR CAUGHT: cleaning up before exit
THE ERROR WAS:
ERROR: ['ssh', '-oBatchMode=yes', 'user@localhost', 'mkdir', '-p', 'user/cylc-run/mot-aa850']
use --debug to turn on exception tracebacks)
```