new API method: getResourceString

Conflicts:
	src/org/geometerplus/android/fbreader/api/ApiMethods.java
	src/org/geometerplus/android/fbreader/api/ApiServerImplementation.java
Merge branch 'master' into ice-cream-sandwich
Merge branch 'ice-cream-sandwich' into yota2
Merge branch 'yota2' into kindle