mimeview: Fixed !JavaScript syntax highlighting with Pygments, by working around Pygments not knowing the `application/javascript` MIME type.
mimeview: Fixed !JavaScript syntax highlighting with Pygments, by working around Pygments not knowing the `application/javascript` MIME type.

Closes #9288.

pkdevbox/trac,pkdevbox/trac,pkdevbox/trac,pkdevbox/trac