Google Distance Matrix api & Walking Time support

Feature detail:
Added support of calculating walking time between source location and
all destination location in project using Google Distance Matrix api.

Details:
1. Implemented query builder, response handler, XML parser, HTTP request
for Google distance matrix api processing.
2. Added location listener which gets the current device geolocation
3. Added support of updating all destination items in UI with the data
retrieved from api call.
4. On refreshing the list, repopulate the data so that updated time is
displayed
5. Code cleanup related to previous checkins.