Don't syntax highlight codebase pattern search results
- This is incredibly slow for non-PHP languages which need to shell out to Pygments.
- A lot of this highlighting isn't very useful anyway, because it doesn't have any context.
Instead, try to highlight pattern matches but don't highlight the source itself.
Reviewers: chad, btrahan
Reviewed By: btrahan
Differential Revision: https://secure.phabricator.com/D12141