Config IMAP auth type (plain, auth or check)

[drdaeman]

Currently, in rcube_imap::connect() (rcube_imap.inc) method connection is performed this way:

$this->conn = iil_Connect($host, $user, $pass, array('imap' => 'check'));

I don't know is it script's problem, or my server's fault (probably the latter), but trying 'auth' (CRAM-MD5 failed for unknown reason) then 'plain' was terribly slow. And I think because both IMAPd and HTTPd are running on the same machine, communicating through loopback interface, plaintext authentification is secure enough. So, I'd suggest maybe this should be a configuration option like this:

// IMAP auth. Can be "auth" (CRAM-MD5), "plain" (PLAIN) or "check" to auto detect.
// Optional, defaults to "check".
$rcmail_config['imap_auth_method'] = 'plain';

PS. Thanks for a great webmail client and sorry for my probably bad English.

[seansan]

Review if wanted in 1.1

[thomasb]

Added to trunk in r1394