Make line selection in source code views less fragile and more consistent
Make the behavior a little simpler and hopefully more robust.
- Clicked commit/revision links in Diffusion, saw the links get followed instead of the lines highlighted.
- Highlighted lines in Diffusion, saw just the line/code highlight instead of the whole thing.
- Highlighted lines in Paste and new-style Harbormaster build logs, saw consistent behavior.
Reviewed By: amckinley
Maniphest Tasks: T13105
Differential Revision: https://secure.phabricator.com/D19348