cmd/hiveview: viewer app update (#696)

A big update for cmd/hiveview.

- All external resources are now bundled in hiveview, so the app can run without
  Internet access.
- External CSS/JS libraries have been updated to the latest version.
- The index page and suite page are now separate documents. This makes browser
  navigation work better and is also a bit cleaner in the JS implementation.
- When loading suite data and large log files, a progress bar is shown.
- The 'expand' button in the test list was a bit confusing because it had a
  green icon when closed, and a red icon when opened. Since this was the only
  colored element on the page, it could be mistaken for test status. In the new
  version, the list of tests now shows red arrows for failed tests and gray ones
  for passed tests.
- It is now possible to link to a test. When clicking on a test in the list, the
  test becomes 'selected', which is indicated by a yellow background. The
  selected test is stored in the page URL.
- Output from tests is now limited to 50 lines to avoid freezing the browser. If
  there is more output, a link to the log viewer is shown. The log viewer can
  now display the output of a single test.
- In the log viewer, a link back to the test is shown. This is useful when
  sharing a client log file with someone else, since they can go and check out
  the test case that generated the log.
- Test output lines starting with `FAIL:`, `ERROR:` or `Error:` are shown in
  bold text.
- The suite page now shows the duration of each test, as well as the overall
  suite duration and start time.
- The new page header shows the hive commit and build date. This information is
  taken from `hive.json` in the workspace, so it will update whenever hive runs.
- When a simulation run times out, hive now stores a `timeout` flag in the test
  results. The viewer app shows timeouts as a special kind of failure.
- All timestamps are once again shown as local time. They were changed to UTC in
  commit beebe58, but I've since figured out how to sort by the ISO
  string and only convert to local time for display.