[sync] session ids

[Anthony Mills]

Does anyone think this will causes any problems?

session_id('syncml_' . $sourceRef . '_' . $locName . '_' . $targetRef);

$sourceRef, $locName, $targetRef are sent by the SyncML client, and this 
combination should be unique.  I know this is not secure, but the only 
other choice I can think of is to have a mapping, in which case it is 
insecure anyway.  If we are truely paranoid, we could use the value 
returned by the password field, if it exists.

Thanks,
Anthony