[PATCH 2/3] gitweb.cgi: git_blame2: Allow back-trekking through commits

This patch adds the capability of back-trekking through
commits from git_blame2() as follows:
blame2->commit->blame2->commit->blame2->...->initial commit.

Signed-off-by: Luben Tuikov <redacted>
---
 gitweb/gitweb.cgi |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)