scrollabel flash cards a bit more memory optimized and turning of acra if not in release build config and using the first datum as instructions and making images show in the image view not hte video view...

fixes https://github.com/OpenSourceFieldlinguistics/FieldDB/issues/1537
fixes
https://github.com/OpenSourceFieldlinguistics/FieldDB/issues/1536
fixes https://github.com/OpenSourceFieldlinguistics/FieldDB/issues/1535
Merge branch 'master' into speechrecognition

Conflicts:
	src/com/github/opensourcefieldlinguistics/fielddb/lessons/ui/DatumDetailFragment.java
	src/com/github/opensourcefieldlinguistics/fielddb/lessons/ui/DatumListFragment.java