Refactored StumblerService, moved bound usage to ClientStumblerService,
this is not used by Fennec.
The max bytes stored on disk, and the max weeks on disk, are now final
and set in the constructor of DataStorageManager, rather than setter
functions.
Change function name storageIsEmpty to notifyStorageStateEmpty
- Added defines for delay for starting upload, frequency of upload in
active mode.
- Added code to guard against passive upload being scheduled
more frequently than every 5 mins.
- Documented use of limiting values in DataStorageManager.
- Added guard limits to the number of cells and wifis that can be
  converted to JSON (and then stored by the DataStorageManager)