Adding test for child var types and ignoring builder outputs and aggregation return vals

Hello eford1, 

Please review the following commits I made in branch 'azulus-types'.

6ac3d29277eba4cd8f6ff9ece6d71984299e6095 (2013-04-23 16:07:13 -0700)
Adding test for child vars and ignoring builder outputs and aggregation return vals

R=eford1