changes since 1.0:
I've added two new settings for subforms.
* #data_separation, defaults to on: Separates the data in $_POST to avoid name conflicts
* #subform_after_build: This just adds #after_build functions for you to the subform. Useful for customizing subforms.
Here's first version for 5.x. Have fun. Report bugs.
This version doesn't require any db changes from 4.7. Just install and you should be good to go.
There was a mistake in 5.x-1.0 that this version fixes.