Firefox SVG patterns path issue workaround

The Github description of the Firefox "bug" seems misleading. If I've read the linked bug correctly:

- the bug is in the HTML5 spec., not in Firefox

- Firefox implements the spec. correctly

- other browsers don't conform to the spec.

- Mozilla have attempted to get the spec. fixed, but Ian Hickson has been obstinate

There's certainly an argument to be made for Firefox ignoring hixie and the spec. and just doing what works, but the Github description is still painting this in a very skewed way that isn't representative of the issue.