Author: Paul Holden
MDL-76154 blog: add files/attachments to custom report source.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=224b3ab51f1e76aa48666f739c115dfb2b811372
http://github.com/moodle/moodle/commit/224b3ab51f1e76aa48666f739c115dfb2b811372
+ 4.2 en [blogattachment,core_blog]