Change to process name if the numprocs greater than 1

According to the documentation [1] the process name has to be changed
if the numprocs value is greater than one.
At the moment this can be achived by defining the process_name manually
in the right format.
This enhancement helps to auto set the process_name the right way.

[1] http://supervisord.org/configuration.html#program-x-section-values
Merge pull request #38 from dol/fix/change_process_name_on_numprocs_gt_1

Change to process name if the numprocs greater than 1