Merge changes made in Gnus trunk.

Merge changes made in Gnus trunk.

mm-view.el (mm-display-shell-script-inline): Fix typo in docstring.
 (mm-display-javascript-inline): New function.
mm-decode.el (mm-inline-media-tests): Add application/javascript viewing function.
nnimap.el (nnimap-open-connection-1): Store the actual stream type used.
 (nnimap-login): Prefer plain LOGIN if it's enabled (since it requires fewer round trips than CRAM-MD5, and it's less likely to be buggy), and we're using an encrypted connection.
proto-stream.el: Alter the interface functions to also return the actual stream type used: network or tls.