User stored secrets

[Adam Schreiber <sadam clemson edu>]

My thought for adding a method for users to store arbitrary secrets in
gkr is to create a user keyring and store user created secrets there
by default.  In the creation dialog, the user would have the option of
selecting other keyrings to store it in.  The unlock password would be
automatically generated and stored in the login/default keyring so the
separate keyring would automatically be unlocked.

I think we should be pushing this paradigm of namespacing keyrings to
the various gkr consumers (webkit, network-manager, evolution,
empathy, etc).

Cheers,

Adam