Git commits in Moodle 3.4.1 by Carson Tam

commit 65e260281bea3870e894352a781b45d33f5690ce
Author: Carson Tam <carson.tam@ucsf.edu>
Date:   Tue, 28 Nov 2017 06:47:53 +0800
Tag:    v3.4.1

MDL-60161 class curl in filelib: Cleaned up doc block.

commit f29bd28d6a7f875d577b0ee67e0c1b0c26e5d350
Author: Carson Tam <carson.tam@ucsf.edu>
Date:   Thu, 28 Sep 2017 23:46:31 +0800
Tag:    v3.4.1

MDL-60161 class curl in filelib: Avoid duplicate params in http header