HTCONDOR-1284: Condor_history Ability to read epoch ads
HTCONDOR-1284: Condor_history Ability to read epoch ads

-PR requested changes 1
   -Changed increment semantics
   -Made tool error out if passed object is not a directory
   -Removed later verification check for directory existing
    as it is now obsolete

htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor