Denote a symbolic link in side-by-side viewer

When code reviewing a symbolic link it is hard to tell from a regular
file that just happens to have the same content.  Make the symbolic
link more obvious by showing "File Type: Symbolic Link" at the top of
a symbolic link content.

Bug: issue 622
Change-Id: I4cfbae0523e05320773938e8dc871eb8bf592977
Signed-off-by: Shawn O. Pearce <sop@google.com>
7 files changed