Bump version number to 3.0.4

Release 28

add dragscrollable.js to BookReaderDemo/index.html [mang]

fixes https://bugs.edge.launchpad.net/bookreader/+bug/456780

Fix race condition in select call. Fix fallback code so it properly d…

…etermines available reduction levels from JP2s.

Release 26

Release 25

Release 24

Release 23

Release 22

Release 0.9.21