fixed "plugin => library => back" sequence behaviour
synchronization with beta branch: introduced FBReaderApp.ExternalBook field
Merge branch 'master' into beta
Merge branch 'master' into ice-cream-sandwich
Merge branch 'beta' into beta-ics
Merge branch 'ice-cream-sandwich' into beta-ics
Merge branch 'ice-cream-sandwich' into yota2
Merge branch 'beta-ics' into betayota

Conflicts:
	src/org/geometerplus/android/fbreader/FBReader.java
Merge branch 'yota2' into betayota
introduces FBReaderApp.getCurrentBook()
Merge branch 'master' into ice-cream-sandwich
Merge branch 'beta' into beta-ics
Merge branch 'ice-cream-sandwich' into yota2
Merge branch 'master' into beta
Merge branch 'ice-cream-sandwich' into beta-ics
Merge branch 'beta-ics' into betayota
Merge branch 'yota2' into betayota
code simplification
Merge branch 'beta' into beta-ics
Merge branch 'beta-ics' into betayota