Rewrite beaker urls

/beaker/<container_id>/foo -> /foo
Make Node and IPython plugins respect relative UI path.
Remove writeVersion

We don't need to log to version.html file
Allow non-localhost hosts

Continue 09139fe0c179de21a076e287807b309a6437711e
Vendor compile & bower assets
Remove bk.helper (bad merge)
Remove evaluator
Remove bkHelper from bunsen dependency (bad merge)
Revert 3e918521b7abd83c7513df6e3ae849829d3b35e5

Due to fixes upstream in
https://github.com/twosigma/beaker-notebook/commit/2a183d176a1b13b45a27378a41c06c9ae45bffdb#diff-2ef84ec0d988e73f490e47e621cd85fcR318
Fix leading / issue with ipython evaluator
Make asset paths relative
Prevent python auth redirect

without this the request would try to redirect to

beakernotebook base url /bunsen
which would kick into a 400 which would then
makes the page think the login did not work, which then
prevented the kernal evaluator from ever loading.
Add better cell bodies
Re-add default notebook javascript cell output

(bad merge)
Persist query params when opening a new notebook.

This broke due to changes introduced in
https://github.com/twosigma/beaker-notebook/commit/385af6959144922f083ca81d3ccf3df4ba0eae5c

which redirects the open to a session based url. Because of the redirect
we were losing the query parmas that were initially sent. The query
params contained info that was needed within a nested iframe env.