Git commits in Moodle 3.7.1 by Bas Brands

commit 40271e858d9aad5e193f0315d859ebab3b5f7aca
Author: Bas Brands <bas@moodle.com>
Date:   Mon, 24 Jun 2019 20:27:14 +0800
Tag:    v3.7.1

MDL-64935 theme: prevent activitynavigation link overflowing container

commit f839aff2b5b0c6f1275eb7538bddda66006e88db
Author: Bas Brands <bas@moodle.com>
Date:   Wed, 19 Jun 2019 18:07:52 +0800
Tag:    v3.7.1

MDL-65105 theme_classic: use $dark variable for navbar-dark

commit 4af9077f26f637bfe254a3f69dbff4be8b967b1b
Author: Bas Brands <bas@moodle.com>
Date:   Tue, 21 May 2019 23:07:31 +0800
Tag:    v3.7.1

MDL-61319 themes: prevent using @extend rules for complex classes