generate app/404.static.jade during deploy process, and remove it from master (ref. issue #26)
ignore 404 jade
alert style
better error message
Filtering by label in full structure instead of only names.

The github api return {color, name, url} structure for a label. Since we
plan to add more rich presentation, we should deal with labels in this
structure instead of only names.
Show predefined/other labels in issue list.

- Predefined labels are configured in app/jsenv.json.
- Predefined labels share same data structure as with labels in github
  api.
- Group labels together by predefined/other in Chosen dropdown.
- Colorize labels using colors defined in jsenv or github.
- Style project name label in badge instead, to standout it.
- Multi-label filter are AND together instead of OR together.
Merge branch 'master' into issues