Merge remote-tracking branch 'tbx/master'
Only set firstPlay when actually playing
Put setting of firstPlay into progress handler
Simplify, simplify, simplify
Merge pull request #618 from saebekassebil/firstplay

Pull in firstPlay fix from stable (2.1.x)
Remember to call play with parenthesis
Forward-slashes in Windows builds
Merge pull request #624 from saebekassebil/wincake

Forward-slashes in Windows builds
Don't read up the cover-image of books
Add aria labels to player controls
Meaningful labels for playback rate settings
Only focus on pause/play button when its state is changed
Make loading messages role='alert'
Fix that the player stops when selecting the current active section
Fix that the player would pause when selecting the active book from the
bookshelf

We're fixing this with an ugly fix, that appends a "from" parameter to
the url, when redirecting to the book player from the bookshelf. But it
works...
Merge branch 'a11y' into 2.1.x
Merge branch 'a11y' into beta2
Merge branch 'chapterbug' into beta2
Merge branch 'fixbookshelf' into beta2

Conflicts:
	src/view/render.coffee
Fix book-current-playing icon bug and remove legacy _icons file