#1233 Empty patch transforms cause an exception

[Heath Stewart]

Transforms that would otherwise be empty after filtering are causing an exception to be thrown.

This was feature http://sourceforge.net/tracker/index.php?func=detail&aid=1878437&group_id=105970&atid=642717, but this should be supported. The exception is actually thrown during bind, thus breaking the ability to skip empty transforms.

The purpose is to author patches without applicable products in mind, and allow wix during filtering to only produce transforms for products that have those resources in the patch families.

[Heath Stewart]

This isn't reproducible with WiX v3.0.4519.0.