Add options menu to target overview to allow creation of new targets
Add activity to allow creation of new targets
Move population of target overview from db to onResume which will refresh the list after creating a new target
Add delete all targets action to options menu of target overview
Add refresh action to options menu of target overview
Add context menu to target overview
Change name of CreateTargetActivity to SaveTargetActivity
Add logic for editing existing targets and saving them to the database with same id