The main difficulty in tracing async requests which are made during
the rendering of Angular-based pages is tracking the root request (the
one which was made to render the skeleton page which then initiated
all other requests) throughout other requests, so they form a cohesive
trace. This is solved by capturing the root request id and exposing it
as a profiler module constant in the process of interpolating
_scripts.html Django template. Then if that constant is not an empty
dictionary, profiler module intercepts all Angular requests and adds
osprofiler headers to them.
This patch also fixes issues which arose after transitioning to the
new version of angular-bootstrap.