Add the log level and category name in the output. Only output the
thread ID and function name for qCDebug statements as they are not
necessary for general use and make the log harder to read.
Also make sure that the message pattern is set when NO_MSG_HANDLER is
used. Using an environment variable should have priority over it anyway.
The csync log level was only set up on startup, and for log files.
Fix the issue by making Logger::isNoop rely on being explicitly activated
for the log window instead of relying on the presence of a connected
signal, and move the csync log level logic in Logger.
