HPCC-825 Change Resubmit and Restart buttons to be less confusing

Restart currently does what Resubmit used to do, which was to reset
and restart the workunit from the beginging.  Instead Resubmit now
tries to recover the workunit from where it left off.

THis will change the Resubmit behavior of back to what it was previously.

Also adds a "Recover" button which will attempt to begin the workunit
from where it previously stopped.

Tooltip improved to better explain what will happen.

Signed-off-by: Anthony Fishbeck <Anthony.Fishbeck@lexisnexis.com>