Modified grapher.py for new template names, added template error.

Grapher.py works with the modified graph template file names.

If the none of the 3 predetermined templates exist in the user's current
directory, the program exits with a system error message.

BUG=none
TEST=manual

Change-Id: Ib79772e3c8df86b3c730736de87c36eed637162d
Signed-off-by: Amy Zhang <ayzhang@chromium.org>
1 file changed