Fixed bug in Impute whereby parents that were not PyMCObjects (e.g. scalars) could not be properly handled.
Fixed bug in Impute whereby parents that were not PyMCObjects (e.g. scalars) could not be properly handled.

git-svn-id: 1df7fcefc24ce524793a7474bd98e66739d04a42@1178 15d7aa0b-6f1a-0410-991a-d59f85d14984

matthew-brett/pymc,matthew-brett/pymc