Using "@nnn" as a suffix on the URL token will open the file at
the given line on the B (right) side of the file. "@aNNN" can be
used to open the file relative to the line NNN on the A (left) side.
In the History section of ChangeScreen2 hyperlink each line number
to the line that comment appears on.
Bug: issue 348
Change-Id: I37de37d63d5deb6dc38f040e7e9b2bf5b09ef909