optionally turn encryption on or off in the XMPP connection

For identi.ca, we had some problems with the XMPP daemon getting
"stuck" in I/O through the encrypted (by default) XMPP socket. Turning
off encryption helped. So, now it's an option.

darcs-hash:20080826131814-84dde-2c4a809c6fb666dfb4b96d0d61205fe418f4e4b4.gz

config.php.sample

@@ -54,6 +54,7 @@ $config['db']['database'] = 'mysql://laconica:microblog@localhost/laconica';
 #$config['xmpp']['server'] = 'server.example.net';
 #$config['xmpp']['port'] = 5222;
 #$config['xmpp']['user'] = 'update';
+#$config['xmpp']['encryption'] = false;
 #$config['xmpp']['resource'] = 'uniquename';
 #$config['xmpp']['password'] = 'blahblahblah';
 #$config['xmpp']['public'][] = 'someindexer@example.net';

lib/common.php

@@ -86,6 +86,7 @@ $config =
 			  'server' => 'INVALID SERVER',
 			  'port' => 5222,
 			  'user' => 'update',
+			  'encryption' => true,
 			  'resource' => 'uniquename',
 			  'password' => 'blahblahblah',
 			  'host' => NULL, # only set if != server

lib/jabber.php

@@ -82,7 +82,8 @@ function jabber_connect($resource=NULL) {
 								XMPPHP_Log::LEVEL_VERBOSE :  NULL
 								);
 		$conn->autoSubscribe();
-
+		$conn->useEncryption(common_config('xmpp', 'encryption'));
+		
 		if (!$conn) {
 			return false;
 		}