Added extra null-check.
Added null check.
Extra null check
Merge branch '2.1_bugfix'

Conflicts:
	src/net/nightwhistler/pageturner/activity/ReadingFragment.java
	src/net/nightwhistler/pageturner/view/bookview/BookView.java
Disabled dragging the navigation drawer.

It conflicted with other motion-based controls like swiping and dragging
the progress bar.
Removed requestFocus call
Now remembers last activity.
Fixed NullpointerException