device-specific methods moved to enum
Merge branch 'master' into nook

Conflicts:
	src/org/geometerplus/zlibrary/ui/android/library/ZLAndroidLibrary.java
Device.isEInk() method
Merge branch 'master' into nook
Eink -> EInk
ZLAndroidLibrary.Device => DeviceType
Merge branch 'master' into nook

Conflicts:
	src/org/geometerplus/zlibrary/ui/android/library/ZLAndroidLibrary.java