Make a bunch of static changes to sheriff-o-matic.

-A bunch of minor UI tweaks to get things to line up better.
-Align the examine/snooze buttons vertically so they take up less space.
-Make the tabs in ct-results-by-builder black and more tab-looking.
-Change the name to Sheriff-o-matic now that it's clear we're sticking with it.
-Add a useful links link to the right of the revisions.

BUG=400411,400398
NOTRY=true

Review URL: https://codereview.chromium.org/462363003

git-svn-id: svn://svn.chromium.org/blink/trunk@180294 bbb929c8-8fbe-4397-9dbb-9b2b20218538