#51 #53 fixed. Still has minor UI problems

Added null returns to CRUD. Added checks in queries of list, items to
the edit activities. Also added it to main activity loadlists()
function. Still needs slight modification. Updated prototype code for
randomList(). Needs passed a list similar to DBList.items that instead
contains the id's of the tabs for the group selected. Also needs tab
switch method implemented, it's commented where.