After server start, load a page silently to avoid a delay on first view

Will fail silently (without issue) if curl is not installed.
Tweaks to CachedPassword mechanisms, and decreased student iters on Pi.
Merge branch 'release-0.11.1' of github.com:learningequality/ka-lite into tweaks_from_nalanda_testing
Merge remote-tracking branch 'upstream/release-0.11.1' into tweaks_from_nalanda_testing
Spacing/wording tweaks on coach report titles.
Exclude unavailable videos from the search's autocomplete results.
Merge branch 'tweaks_from_nalanda_testing' of github.com:jamalex/ka-lite into tweaks_from_nalanda_testing
Merge pull request #1160 from jamalex/tweaks_from_nalanda_testing

Several tweaks to address issues identified during Nalanda testing