Setup :attr:`wasp_launcher.apps.WAppsGlobals.log` configuration. Reads defaults and
		override it by a file given via :attr:`WConfigApp.__environment_file_var__` environment variable.
		After that configuration files are applied from :attr:`WConfigApp.__environment_dir_var__`

		:return: None

def read_config(cls):
		""" Setup :attr:`wasp_launcher.apps.WAppsGlobals.log` configuration. Reads defaults and
		override it by a file given via :attr:`WConfigApp.__environment_file_var__` environment variable.
		After that configuration files are applied from :attr:`WConfigApp.__environment_dir_var__`

		:return: None
		"""
		WAppsGlobals.config = WConfig()

		def load(filename):
			if os.path.isfile(filename) is False:
				raise RuntimeError("Invalid configuration: '%s'" % filename)
			WAppsGlobals.config.merge(filename)
			WAppsGlobals.log.info('Configuration loaded from file: %s' % os.path.abspath(filename))

		load(cls.__configuration_default__)

		if cls.__environment_file_var__ in os.environ:
			WAppsGlobals.log.info('Variable %s was set' % cls.__environment_file_var__)
			load(os.environ[cls.__environment_file_var__])

		if cls.__environment_dir_var__ in os.environ:
			WAppsGlobals.log.info('Variable %s was set' % cls.__environment_dir_var__)
			config_dir = os.environ[cls.__environment_dir_var__]
			if os.path.isdir(config_dir) is False:
				WAppsGlobals.log.error(
					'Invalid configuration directory was specified: "%s"' % config_dir
				)

			entries = list(os.listdir(config_dir))
			entries.sort()
			for entry in entries:
				config_file = os.path.join(config_dir, entry)
				if os.path.isfile(config_file) is False:
					WAppsGlobals.log.error(
						'Invalid configuration "%s" in the directory "%s"' %
						(config_file, config_dir)
					)
					continue

				load(config_file)