DB saves resource filenames for weather icons

[loganSims]

issue #83

Implementation Notes

• Changed the value of column MOUNTAIN_PASS_WEATHER_ICON from INTEGER to TEXT. This is so we can save the weather icons as their filename.
• The magical line that maps a filename to the resource ID. getResources().getIdentifier(cursor.getString(cursor.getColumnIndex(MountainPasses.MOUNTAIN_PASS_WEATHER_ICON)),"drawable", getActivity().getPackageName());
• Bumped DB version to 6.
• Data migration logic. Used a transaction, on any failure will clear database.
• Upgrading worked fine on the simulator. Should probably be tested on a physical device.

[waynedyck]

Added a few mountain passes as favorites in a previous version and then applied this update. The logic for the database scheme change ran and maintained my existing favorites.

[waynedyck]

Merged with commit c427b64850429e1b66c6889c76566fd8dc70116c