Add webLink support for commit parents in change screen

This change moves webLinks from RevisionInfo to CommitInfo
because the parent commit and the commit is both on RevisionInfo
level and for the weblinks to be unambiguously connected to the
respective commit it needs to be on the commit level.

Change-Id: I2f79b451f88070ae674aefe2dfe4a9df3f5a8ef1
11 files changed