Allow configuration of logging rules from outside of the application,
either through a configuration file (.config/QtProject/qtlogging.ini),
or through a file specified by a QT_LOGGING_CONF environment
variable.
The logging rules from the different sources are concatenated: First
the rules from QtProject/qtlogging.ini are applied, then
QLoggingCategory::setLoggingRules(), finally from the environment.
This allows an application to overwrite/augment the system wide rules,
and in turn that can be tailored for a specific run by setting a
configuration in the environment variable.
[ChangeLog][QtCore][Logging] The logging framework can now be configured
with an .ini file.
Change-Id: I442efde1b7e0a2ebe135c6f6e0a4b656483fe4b1
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
a2bfd11493