"category default" clause was found in a logging statement.
When setting defaults, use ISC_LOGCATEGORY_DEFAULT for the category parameter
instead of NULL.
Don't do the isc_log{category,module}byname lookup every time through the
loop in logconf.c:category_fromconf(); it can be done just once, before
entering the loop.
return an isc_logconfig_t. isc_log_cretechannel and isc_log_usechannel
now take an isc_logconfig_t instead of an isc_log_t; this is to address
reconfiguration in a multithreaded environment.
isc_logconfig_create, isc_logconfig_get, isc_logconfig_use and
isc_logconfig_destroy were added to work with the new isc_logconfig_t type.
isc_logregister_categories and dns_log_init are now both void rather than
returning isc_result_t.
