[MOD] Server: port added to start/stop server strings
[FIX] RESTXQ: don't convert empty sequence to values
[MIN] XQuery, casting: return Empty.SEQ instead of null
[MOD] PHP client updated (thanks to James Ball)
[MIN] minor refactoring
[MOD] RESTXQ: allow "rest" as alternative RESTXQ prefix
[MIN] refactorings
[MOD] XQuery: several refactorings to simplify creation of XML fragments