[Feature]
1.add about dialog 
2.Still lack image element
[Feature]
1.add about page and this content
2.add fb page redirect , website redirect , and send to emal in about
page
[Freature]
1.add share to email in bookviewer
2.add share to google plus in bookviewer
3.create package *.view
4.move some class to view
[Feature]
1.add about dialog into all fragment
[Feature]
1. update version code and version name