Integrate UI text strings from doc

@cahrens @mhoeber @explorerleslie 

Changes are visible at http://studio.benmcmorran.m.sandbox.edx.org/.
> @cahrens  Does this look OK to you? I know you recently changed this code.

yes, it does. New-window functionality is preserved, and title setting is a bit smarter about not overwriting titles when they are present. 

Just may be it would be good to impove https://github.com/edx/edx-platform/blob/bulk-publishing/lms/static/js/verify_student/photocapture.js#L332 too.