Version 1.1.4 – Fix Windows credentials storage

The primary change in this version is the use of a new home-grown replacement for oauth2client.client.token_storage that stores the credentials in an encrypted file rather than in the keyring password field. The original implementation of oauth2client.client.token_storage stores the credentials from Google as the value of the password in a call to keyring.set_password(...). Unfortunately, this fails on Windows because of size limitations on the length of passwords. The replacement implementation stores an encryption key in the password field instead, and uses that encryption key to encrypt a file that stores the credentials on disk.