Fixes exception thrown when leaving My Trips and My Notes.

Fixes exception thrown when leaving My Trips and My Notes edit screens.
The exception was caused by using AdapterView count of items to reset
colors in ListView widget.  It seems that ListView widget does not
necessarily render all of the items of the CursorAdapter.  Fixes #5.
Merge pull request #17 from mafiglio/FixBug_0005

Fixes exception thrown when leaving My Trips and My Notes edit mode.