keyring issues

Funny fact #1: keyring chooses SecretService.Keyring if I launch the app from $HOME (using virtualenv). This is probably a keyring issue.

Our bug: global name "secretstorage" not defined.

2013-09-19 18:36:10,892 - leap.bitmask.util.keyring_helpers - DEBUG - Selected keyring: 
2013-09-19 18:36:10,893 - leap.bitmask.gui.mainwindow - ERROR - Problem saving data to keyring. NameError("global name 'secretstorage' is not defined",)
2013-09-19 18:36:10,895 - leap.bitmask.services.eip.providerbootstrapper - DEBUG - Checking name resolution for dev.bitmask.net
2013-09-19 18:36:10,907 - leap.bitmask.services.eip.providerbootstrapper - DEBUG - Checking https for dev.bitmask.net
2013-09-19 18:36:20,909 - leap.bitmask.services.eip.providerbootstrapper - DEBUG - Downloading provider info for dev.bitmask.net

(from redmine: created on 2013-09-19, closed on 2014-08-14, relates #4083 (closed), relates #5915 (closed))