Implement panic functionality

Task #2261
Handle delete data files
Merge branch 'master' into task_2261_panic_button

Conflicts:
	app/src/org/witness/informacam/app/WipeActivity.java
import fix
Merge branch 'task_2261_panic_button' of https://github.com/mikaelvonpfaler/iWitness into mikaelvonpfaler-task_2261_panic_button