Add earthquake information segment

This segment currently only looks at the 'goo' earthquake rss feed,
which takes it's information from the Japan Meteorological Agency.
This segment can be customized to display recent earthquakes that occur
in a given 'alert-window' above a certain magnitude threshhold. This
information should not and cannot be used as an early warning system,
but is helpful in alerting you to large quakes that may have happened
nearby.
Merge pull request #122 from scicalculator/add_earthquake

Add earthquake information segment