Security update to 4.8.4
Addresses three security advisories: PMASA-2018-06, PMASA-2018-07,
PMASA-2018-08.
Also includes additional non-security related code updates.
ChangeLog: https://www.phpmyadmin.net/files/4.8.4/
PR: 233953
MFH: 2018Q4
Security: ed10ed3f-fddc-11e8-94cf-6805ca0b3d42