This corrects the tab titles on the project page which currently
typically just say "master", "master", "master", ... because they
all display the default branch of the project stanza.
Instead, use the branch of the source context for the project stanza,
or, if the project stanza is not from the current project, then
use the name of its project.
This causes them to appear like:
"openstack/project-config", "master", "stable/diablo", ...
Also, update the entire Project page component hierarchy to use
hooks instead of classes.
Update the styling on the H2 element so that we can have the
refresh icon share the same vertical space (so that we don't have
large amounts of wasted vertical space at the top of each page.
Change-Id: I863e0eb4a7f20ee6363e596e61cc49b2cbc22953