nginx @1.0.11 - Enhancement adding new variants

[nicholas@…]

Attached is a patch for the Nginx portfile that adds three new variants:

+image_filter - Enables the Nginx image filter module (​http://wiki.nginx.org/HttpImageFilterModule)
+mp4 - Enables the Nginx MP4 streaming module (​http://wiki.nginx.org/HttpMp4Module)
+xslt - Enables the Nginx XSLT filtering module (​http://wiki.nginx.org/HttpXsltModule)

I'm new to the art of portfile writing, so suggestions are welcome!

[ryandesign@…]

An (updated?) patch for this is submitted in #34188.

[cal@…]

Added in r92282, although I didn't use your patch (because I didn't see it).