fix for controls that hide if keyboard scrubbing

In version 2.9, I reported issue #548, that controls hide when using
keyboard to scrub even if the alwaysShowControls option is set to
"true." Pull request #569 merged this fix, but did so in the /build
directory. It appears that fix did not move forward with versions and
the issue is occurring in the latest version. Adding fix in the /src
directory so that future builds get the fix.
adding controls fix to build and minified versions
Fix for issue #754, no duration display w/jQuery 1.9

Removed leading and trailing spaces in timeAndDurationSeparator to work
around change in jQuery selector build rules as detailed in comment to
issue #754 by marshallbu.
timeAndDurationSeparator fix added to build
Fix for issue #902

In build tracks function, I added a check to see if the browser will
attempt to do present captions natively. (Currently only a feature in
Chrome. Outside of mejs, my if statement would include a check to see
if any textTracks were declared (t.domNode.textTracks.length > 0), but
the buildtracks function already checks for player.tracks.length.) If
this is true, we prefer to use mejs captions and loop through the
textTracks to set their mode to "hidden" to prevent display.
textTracks fix added to /build
Merge pull request #923 from peterh-capella/master

Multiple fixes: old issue #548, current issues #754 and #902