Making it possible to tab to captions.

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.
Fixed styling for volume button.

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.
Removing JavaScript qTip tooltips.

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.
Fixed failing test for VideoAlpha caption heiht.

It turns out that there was wrong invocation of toBeCloseTo() function. Most likely a typo.
Updated the readme.
Made it so that keyboard also prolongs auto hiding of controls.
Fixed bug dealing with empty subtitles Url string.

Now when subs parameter is empty or the YouTube IDs are not specified,
captions will not try to fetch non-existent file.
Styling improvements.
Volume and speeds dialogs are fully extended.

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.
Replaced Video with VideoAlpha.

Now all Video tags and VideoAlpha tags will be handled by VideoAlpha.
Fixed test for height of player when CC is disabled.

It turned out that we were reading the heights of the contols and other elements
before we initialized the heights.
Changed back handling of Video by original Video code.
Removed unnecessary commented out code from Jasmine tests.
Removed some more comments.
Fixing tests related to fetching YouTube metadata.

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.
Improved strings in template.

Only relevant part of string will go through the Python internationalization function.
Turned off all VideoAlpha Jasmine tests.
Making it possible to tab through individual speeds.

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.
Enabled tabbing to volume slider.
Removed unnecessary leading and trailing spaces from heading in template.
Merge pull request #593 from edx/valera/captions_keyboard_access_2

Valera/captions keyboard access 2