I've attached an SVN patch, based on the trunk as of 12/24/2008, that implements this feature. The patch includes a new advanced property called "build property files". I had previously posted an older version of this patch to
IVYDE-90, not realizing the subtle differences between the two issues.
We use ivy parameterization in our build environment, which is resolved using our ant build files and properties. Because IvyDE works outside of that environment, we needed a way to provide IvyDE with the build.properties file.