Merging edge to master finally

Implement record locking for Android to prevent multiple AsyncTasks from attacking the database simultaneously to prevent same record persisted to server multiple times

bump version to 0.4.1

Odometer

Implementing new Odometer feature for tracking distance-travelled.  Simple js API:  getOdometer, resetOdometer.  It's up to developer to reset the odometer as desired, it will be preset to zero at boot

Bump edge version as 0.4.0

This reverts commit bb2b4ded.

Bump version to 0.4.0

Expand persistence layer

Merge branch 'expand_persistence_layer' of github.com:christocracy/cordova-background-geolocation into expand_persistence_layer

Always persist locations, no matter if HTTP feature is enabled.  Implement getLocations and sync methods for fetching/syncing locations.  Implement batchSync, autoSync parameters to control nature of HTTP

Update README.md

When settings are changed via setConfig, apply them immediately

Update README.md

Cast timestamp to Javascript new Date() before sending to callback.  …

Cast timestamp to Javascript new Date() before sending to callback.  Fix bug in persistence layer on Android wiht new timestamp ISO-8601 format.  Add device_id to HTTP POST for both Android & iOS