Changes to logger module

There's a new default formatter and one typo fixed.
Logger added to synchronizer
Logger added to manager

It needed request queue as an argument so request module was changed
too to pass it as an argument to listeners.
Updated synchronizer's logs

Operation ID was added and clarity of messages slightly improved.
Logger added to free/busy provider
Calendar Fix after iTIP transport rename
Logger added to iTIP transport
Logger added to XML-RPC module

This was actually replacement and improvement of existing logging to
console.  The main improvement which required changes to request
module was adding masked parameters for logging purposes
(e.g. password).
Escaping XML-RPC string values

& -> &amp; and < -> &lt;
Logger added to DNS module
Logger added to request module

This is only basic logging.  There's plenty more possibilities where
to add additional log messages.
Logger added to calendar component