Git commits in Moodle 2.7.20 by Marina Glancy

commit debff7fe73a9b704538f89b867fb4ad6ee9a0184
Author: Marina Glancy <marina@moodle.com>
Date:   Fri, 28 Apr 2017 12:20:46 +0800
Tag:    v2.7.20

MDL-58740 block_course_overview: check session key

commit 7ab7bd886da9a5b71f3c0d06ba49861a85d064e3
Author: Marina Glancy <marina@moodle.com>
Date:   Wed, 26 Apr 2017 15:04:25 +0800
Tag:    v2.7.20

MDL-58670 blog: respect capability to search entries

commit d4ece04082ae395a1f0cf520508369b11c77594f
Author: Marina Glancy <marina@moodle.com>
Date:   Wed, 19 Apr 2017 12:04:47 +0800
Tag:    v2.7.20

MDL-58635 blogs: check edited blog belongs to current user