Re-implement android background-service.  Migrate control out of the CordovaPlugin and into BackgroundGeolocationService.  This is required for those who may still wish to have the plugin transmit locations to server via HTTP.  Re-implement HTTP layer with same options as free plugin (namely url, params, headers).  There is no persistence layer currently, so when in-plugin HTTP is enabled, the plugin won't re-try when no network is detected.