Merge branch master into develop

This merge puts develop ahead of master.

Conflicts:
dox/pages/language_entities.dox
util/cmake/SeqAnBuildSystem.cmake
util/py_lib/seqan/dox/tpl/css/common.less
util/py_lib/seqan/dox/tpl/css/common.less.css
util/py_lib/seqan/dox/tpl/index.html
util/py_lib/seqan/dox/tpl/js/app.js
util/py_lib/seqan/dox/tpl/js/common.js

Please, Bjorn verify that merge conflicts have been solved correctly - I always preferred changes from *develop*.