Add command line and configuration option to set umask

Issue #1048 identified that files created by keepalived are created
with mode 0666. This commit changes the default to 0644, and also
allows the umask to be specified in the configuration or as a command
line option.

Signed-off-by: Quentin Armitage <quentin@armitage.org.uk>
get_priority(vector_t *strvec, const char *process)
{
	int priority;

	if (vector_size(strvec) < 2) {
		report_config_error(CONFIG_GENERAL_ERROR, "No %s process priority specified", process);
		return 0;
	}

	if (!read_int_strvec(strvec, 1, &priority, -20, 19, true)) {
		report_config_error(CONFIG_GENERAL_ERROR, "Invalid %s process priority specified", process);
		return 0;
	}

	return (int8_t)priority;
}

get_priority(vector_t *strvec, const char *process)
{
	int priority;

	if (vector_size(strvec) < 2) {
		report_config_error(CONFIG_GENERAL_ERROR, "No %s process priority specified", process);
		return 0;
	}

	if (!read_int_strvec(strvec, 1, &priority, -20, 19, true)) {
		report_config_error(CONFIG_GENERAL_ERROR, "Invalid %s process priority specified", process);
		return 0;
	}

	return (int8_t)priority;
}
