changed license to GPLv3, leaving BSD notice intact
(following https://www.softwarefreedom.org/resources/2007/gpl-non-gpl-collaboration.html )
 * added Javascript items
 * added option to hand over (X)HTML code rather than text-only
 * added progress bar
 * added statistic of items used
giving option to hand over (x)html; making ebook check call optional
added GPLv3 license
changed license to AGPLv3