fixed NPE in Bookmark comparator
fixed NPE (?)
VERSION => 1.7.1
compilation issue
fixed exception on unregisterReceiver() call
fixed possible NPE
fixed AndroidManifest.xml: android:changes attribute

Conflicts:

	AndroidManifest.xml
	AndroidManifest.xml.pattern
no android:changes attributes for hidden activities
VERSION => 1.7.2
updated ChangeLog
Merge branch 'master' into book-sort