Create default .conf file for logs with logging disabled.

Currently when DEFINES+=QMF_ENABLE_LOGGING is used all log
categories will be enabled by default, this commit will disable all categories
by default, this way the logging statements can included in the executables
and later logging can be enable/disabled via the settings file and reload by
sending SIGHUP signal to messageserver daemon under unix systems.

Change-Id: I62d9a79f5a02bbeaae17c9a07f9755158116e8fc
Signed-off-by: Valerio Valerio <valerio.valerio@jollamobile.com>
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>