Files without extensions should be able to have their syntax highlighter configured

Following the instructions here, I added this line to stash-config.properties, then restarted Stash:

syntax.highlighter.python.extensions=py,SConscript,SConstruct

Files named SConscript and SConstruct still do not have Python syntax highlighting.

This also might be an issue if highlight.js ever adds support for Makefiles; it would need to both match files ending with *.mk and files named Makefile without an extension.