Ignore DS_Store from now on.
Added check for boormarkable being suitable url.

Added utilities script with generally usable helper methods. Added
checkValidUrl function that checks if URL starts with http:// or
https://, check is case insensitive. Also checked how popup behaves. It
now checks if URL is suitable and only then checks for configuration
being set, authenticates and initializes. Also bumped version number to
0.1.1.