Git commits in Moodle 3.3.4 by Carson Tam

commit d02e847c3f73a62c5e4b69dcb477be4e50ecf112
Author: Carson Tam <carson.tam@ucsf.edu>
Date:   Tue, 28 Nov 2017 06:47:53 +0800
Tag:    v3.3.4

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


commit aab559c464210a2dd171420d5c502953192c6eab
Author: Carson Tam <carson.tam@ucsf.edu>
Date:   Thu, 28 Sep 2017 23:46:31 +0800
Tag:    v3.3.4

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