regexp group in BatchLauncher, no Condor -verbose

Previously I used condor_submit -verbose so that I could pull the job id
from the first line. However, when submitting many jobs it's silly to
have to search through some many lines of output. Now we have a regexp
for Condor that matches on the non-verbose output. Here the job_id is on
the end of the output, so using grouping in our job_id_regexp becomes
very useful. To account for this I have added a job_id_regexp_group
property to the BatchLauncher and it's subclasses. The default of 0
means the whole regexp is matched - however now an integer can be passed
in here to instead select a subgroup of the expression (see
CondorLauncher and the mechanism will be clear).