Git commits in Moodle x.x.x by Stefan Erlachner

commit b1f2b4fdfc1696e97b04cc2cbc4d95b2b51d4bc2
Author: Stefan Erlachner <stefan.erlachner@uni-graz.at>
Date:   Mon, 17 Dec 2018 18:14:15 +0800
Tag:    v3.7.0-beta

MDL-64414 lib/evalmath: add AND, OR functions to evalmath