Fix bugs 1335928 and 1335930.
a. Add support for:
   1. object-values in contrail-logs to determine the object-id values
      for a particular object-type
   2. where * support for object logs in contrail-logs - user can
      just specify object-type without object-id
   3. prefix support for object-id - specified using <prefix*> in
      object-id
b. Refactor start_time, end_time, last parsing code to use the
   relative time support and move parsing common code to opserver_utils

Change-Id: I50b7f197e84e5dc14285016d069ebc016c478458
Merge "Fix bugs 1335928 and 1335930. a. Add support for:    1. object-values in contrail-logs to determine the object-id values       for a particular object-type    2. where * support for object logs in contrail-logs - user can       just specify object-type without object-id    3. prefix support for object-id - specified using <prefix*> in       object-id b. Refactor start_time, end_time, last parsing code to use the    relative time support and move parsing common code to opserver_utils"