precommands with skipped words

[danielshahaf]

It would be nice to have ssh $hostname ls -l and jexec $jname ls -l highlighted; this could be done by extending the precommands mechanism to allow skipping one word before the command name.

[danielshahaf]

Cross-referencing #695.

[danielshahaf]

Incidentally, the arguments to ssh are joined by spaces and split again on the remote end, so ssh $hostname "ls -l" is valid too. Hmm…

(See also #710)