styling of peer review interface for students along with minimal adjustments to the staff grading interface as well. added internationalization of peer grading strings.

visual styling changes to staff grading and peer grading, along with additional instances of the use of the baseline variable instead of pixel definitions for padding and margins.

Update the XBlock version to fix save bugs

give some debug message regarding why export has failed

Prevent student from resetting problem unless they have completed required peer grading.  Grant an exemption if there is no available peer grading.

Valera/captions keyboard access 2

In speed control, when it is focused, a drop down becomes available which contains all
of the available speeds that the player can switch to. When using the Tab button to
tab through all of the controls, it should be possible to select individual speed with
the keyboard.

Only relevant part of string will go through the Python internationalization function.

Previously we were using dummy YouTube IDs such as "slowerSpeedYoutubeId", and "normalSpeedYoutubeId".
This was causing errors when the code tried to fetch metadata from YouTube with that ID. We can't
stub these fetch requests because the data that is fetched is necessary. For example it contains
the length of the video.

It turned out that we were reading the heights of the contols and other elements
before we initialized the heights.

Now all Video tags and VideoAlpha tags will be handled by VideoAlpha.

When the controls receive focus not via mouse click or mouse hover, their appropriate
slider and selection menu are fully extended and shown to the user.

Now when subs parameter is empty or the YouTube IDs are not specified,
captions will not try to fetch non-existent file.

It turns out that there was wrong invocation of toBeCloseTo() function. Most likely a typo.
Updated the readme.

Because sometimes the tooltips generated by qTip get in the way, and the controls becomes
not responsive, it was decided to use standard title attributes for tips.

Also along the way, an error was discoevered in Jasmine tests. It was fixed, but that test is
failing so it was marked specifically to be skipped when all VideoAlpha tests run.

For some reason the "muted" icon was not showing. Styles have been corrected.Now on focus background color is also simplified for div
.volume control.

When a VideoAlpha is present on the page, if the user tries to tab through out the entire page, eventually he will land on the VideoAlpha controls. The tab index order has been set up so that all control receive focus eventually in the order from left to right. When a control receives focus, it is hilighted. The last tab focuses the captions dialog. When the captions dialog has focus, the Up and Down arrows can scroll it up and down.

[STUD-608] django-admin clone_course needs to properly copy metadata as well as draft content