Get Login and storage JSON retrieval working for both main server and dc2 accounts.
Get Login and storage JSON retrieval working for both main server and dc2
accounts.

- Organize the instance variables to distinguish default locations and
  those specific to the account ("my.").
- For clarity, explicitly pass the default_locations.storage_path to
  .set_storage_parameters(), though it's (currently) always the same.
- Make the error reporting thang take status code, rather than entire
  xhr. And use the routine for the top "Temporary server failure."
- Use a 'blather()' routine from misc for debugging messages.

SpiderOak/so_client_html5,SpiderOak/so_client_html5