1094498 - Added logic to re-download rpms, drpms and srpms that don't exist on disk during synchronization
1095332 - updated the position of checking for existing units and associating them with repo, so that the progress calculations are not affected
adding missing type params for get_all_existing_units function
using RPM and SRPM instance's relative_path property instead of calculating relative path at 2 places
Merge pull request #500 from pulp/skarmark-1095332-1094498

Skarmark 1095332 1094498