Git commits in Moodle 3.1.5 by David Monllao

commit c89650cd4220d630b55059b29e82c6ae3d723eab
Author: David Monllao <david.monllao@gmail.com>
Date:   Tue, 28 Feb 2017 18:33:52 +0800
Tag:    v3.1.5

MDL-51833 docs: Move upgrade note under 3.1.5


commit ac4c7623fe0e641d01306a044fe7e625883f65a1
Author: David Monllao <david.monllao@gmail.com>
Date:   Thu, 23 Feb 2017 15:07:44 +0800
Tag:    v3.1.5

weekly release 3.1.4+


commit 2135c7e9ede496bd3736b61ab928178d925d30bd
Author: David Monllao <david.monllao@gmail.com>
Date:   Wed, 22 Feb 2017 16:50:59 +0800
Tag:    v3.1.5

MDL-56206 less: Build css styles after rewrite


commit b2a8d8af063ee7a41441f7d8fc8f4284ff930cfa
Author: David Monllao <david.monllao@gmail.com>
Date:   Tue, 14 Feb 2017 20:44:06 +0800
Tag:    v3.1.5

MDL-56122 editpdf: Fix ghostscript checking


commit 341af0a7795ab2db42587b3370fd105e779ecd2d
Author: David Monllao <david.monllao@gmail.com>
Date:   Thu, 09 Feb 2017 15:00:06 +0800
Tag:    v3.1.5

weekly release 3.1.4+