Create a simple EPUB viewer for Sugarizer

[llaske]

It could be nice to integrate an EPUB viewer in Sugarizer. This activity could work like the Video Viewer activity. The activity could propose few EPUB libraries at startup then browse libraries and start reading the EPUB. This activity could probably use an existing open source EPUB viewer like the one from Futurepress.

Guidelines:

• The activity should be responsive (work on any screen size)
• The activity should work with the keyboard and with the mouse (to support touch screen)
• The activity should use localization library lib/webL10n.js
• The activity should work on any browser (Chrome, Firefox, Safari and EDGE)
• The activity should not use Internet connection (link to local content only) - except to access library content

[llaske]

Added in https://github.com/llaske/sugarizer/commit/a4d198b10634075b1d9d2df1b3cb9008b89bb532

[bzg]

\o/