change in @ translation behavior in maven-resources-plugin 2.3

OpenNMS uses a mixture of ${} and @@ in it's build system for various reasons in filtered properties. The maven resources plugin used to filter both ${} and @@ style properties, but it no longer does so, and as far as I can tell, this change was not documented in the resources plugin documentation. (resources plugin 2.2 uses filtering 1.0-beta-1, and 2.3 uses 1.0-beta-2 AFAIK)

Attached is a simple example that exposes the difference.

If you make the pom.xml use maven-resources-plugin 2.2, the "bar" variable in src/main/filtered/filtered.properties gets converted to "this is bar"
If you make the pom.xml use maven-resources-plugin 2.3, the "bar" variable is no longer interpolated