Try to enter Nirvana after successful initial build

Without this, the board has to wait for the refresh interval to
determine that it can enter nirvana. This extracts the nirvana check and
runs it after all ajax requests finish, so it'll trigger after all jobs
have been fetched.
Always show job stats, even when in nirvana

When we enter nirvana there's no information displayed about the jobs,
which can make it ambiguous as to whether everything is green or if the
radiator isn't finding any jobs. This commit changes the hide/show logic
to hide the job table but leave the summary visible.
Merge pull request #23 from adrienthebo/immediate-gratification

Try to enter Nirvana after successful initial build
Merge pull request #24 from adrienthebo/nirvana-show-stats

Always show job stats, even when in nirvana
Break up job rendering more finely
Add investigate button for failed builds