ant.importBuild should support <ivy:*> tags in the Ant build file

I know how to add to the classpath for Ant taskdefs, but the goal of ant.importBuild() is to support existing Ant build files. Since the Gradle team fully appreciates the beautiful tool Ivy, and Ivy is a major component of Gradle, I think it should support the most common use case for Ant build files using Ivy as documented in the Ivy reference guide.

The average Ant+Ivy user does not write taskdef tasks, they just make sure that an Ivy jar file is in the global Ant CLASSPATH and then use the <ivy:*> tags (per documentations sited above). Seeing as Gradle obviously has Ivy in its own CLASSPATH, I don't see how it could be very difficult to allow it to also be in Gradle's Ant execution CLASSPATH.