Suggested CSL Style changes by Sebastian Karcher

Suggested by Sebastian Karcher to Daniel Himmelstein at the
FORCE2018 Conference. Not yet tested.

The changes focus on dealing with the missing space when authors
are missing and showing editors.

build/assets/style.csl

@@ -16,6 +16,11 @@
   <macro name="author">
     <names variable="author">
       <name initialize="false" initialize-with="" et-al-min="12" et-al-use-first="10" et-al-use-last="true"/>
+      <label form="short" prefix=", "/>
+      <substitute>
+        <names variable="editor"/>
+        <text macro="venue"/>
+      </substitute>
     </names>
   </macro>
   <macro name="venue">