Tooltip to show video progress
Changing the percentage to show no decimal points
Address #1554, #1783, #1813; Minor tweaks to come before pull request

*"Hide Answers" button starts off disabled, toggles based on "Check Answer"
and "Hide Answer" clicks
* "Previous Question" button starts off disabled, becomes enabled as user
progresses through set; "Next Question" button disabled when user gets
to last question
* submit-button click handler has JS confirm function, just need to actually
go through userSelections and look for empty inputs

	modified:   templates/exams/view_exam.html
Merge branch 'master' of https://github.com/Stanford-Online/class2go into wescott-master-exercise-work
Default Hide Answers button to disabled in in-video exercises

	modified:   templates/exams/videotest.js
	modified:   templates/exams/view_exam.html
fixes #1818 video glitches when clicking quiz thumbnail

Candy: adds time labels in each thumbnail.

The glitch is fixed by using a "flip-flop".  When a displayQuestion
event fires, the event disables itself from firing again.  A paired
event .5 second later re-enables the event.  This prevents the
"knife-edge" effect which was causing the repeated looping.
1s -> 0.5s
Complete fix for #1783

Check that user has at least something for each unique named element
or group of elements in a form

	modified:   templates/exams/view_exam.html
Merge branch 'master' of https://github.com/Stanford-Online/class2go into wescott-master-exercise-work
slightly taller slidestrip
small nitty fix
fixed hardcoded 'problem set' in confirm msg
Merge pull request #1824 from Stanford-Online/wescott-master-exercise-work

Wescott master exercise work
Merge pull request #1829 from Stanford-Online/vidya-master-onHover

Show Video Progress text on hover
Merge pull request #1823 from Stanford-Online/jbau-video-glitch

Jbau video glitch
Fix for #1826

Add Show/Hide toggle link for showing/hiding the explanation, because
adding/changing buttons leads to a dark path

	modified:   templates/exams/view_exam.html
Shib backup Metadata file
Merge pull request #1834 from Stanford-Online/jbau-shib-backup-xml

Shib backup Metadata file
Merge pull request #1831 from Stanford-Online/24a2c0775b3394adcf31995c5461292cb2df2afc

Fix for #1826
fixes #1835 no duplicate explanations