Fix searches from repository view
Add word diffs in commit views

This shows changes between adjacent lines rather than just showing the
lines have changed.
Make goblet work in URL subpaths

It is not possible to run it as e.g. http://example.com/goblet/ instead
of needing it to be installed at the URL root.
Always use matching scheme to access fonts

If goblet is accessed over SSL, fetching fonts without SSL triggers an
SSL warning.
Always use flask.sendfile for cache files

Exposing repository files directly seems problematic. This will still
use X-Sendfile when enabled to allow good speed.