[PATCHSET] cg-log cleanups and enhancements

The patchset contains the following 10 patches:

  [PATCH 1/10] Cleanup conversion to human readable date
  [PATCH 2/10] Separate handling of tree and parent in commit headers
  [PATCH 3/10] Separate handling of author and committer in commit headers
  [PATCH 4/10] First parse all commit header entries then print them
  [PATCH 5/10] Move printing of the commit info line inside the loop
  [PATCH 6/10] Remove the catch all rule
  [PATCH 7/10] Move log printing to separate function
  [PATCH 8/10] Move the username matching inside the loop
  [PATCH 9/10] Move file matching inside the loop.
  [PATCH 10/10] Add -s option to show log summary