studio - page headers: added in logic to style page actions' height based on title having a subtitle or not

studio - soft landing: changed strong elem colors to be more subtle since we're not using new nomenclature

studio: nav - clicking anywhere but nav's dropdowns will close them, fixed link outline and is-selected styling

Merge branch 'feature/btalbot/studio-softlanding' of github.com:MITx/mitx into feature/btalbot/studio-softlanding

get to that page once they've logged in.

Merge branch 'feature/btalbot/studio-softlanding' of github.com:MITx/mitx into feature/btalbot/studio-softlanding

index. NOTE: didn't fix old wrong behavior of going to index if not
logged in and tried to navigate to a specific page. Will work on that
next.

Merge branch 'feature/btalbot/studio-softlanding' of github.com:MITx/mitx into feature/btalbot/studio-softlanding

Conflicts:
	cms/djangoapps/contentstore/views.py
	cms/static/js/views/settings/main_settings_view.js
	cms/templates/index.html
	cms/templates/settings.html

ensure old time had a value before comparing it to new time.

On 32-bit Python, this conversion could overflow, for example, for year 2099.  This conversion won't.

change timer to calculate relative duration in javascript