Disable analyzer for SQLite files.
Returns BOOL from methods returning NSError by pointer.

The analyzer complains if methods that return NSError by pointer
do not return something to indicate if there is an error or not.
Modify API to return BOOL from those methods.

Also return the underlaying error in one case instead of hiding
it.
Enable ARC in -Simulator and -Device targets.
Merge pull request #49 from pebble/fix-analyzer-warnings

Fix analyzer warnings