Avoid looking up turbine in global path for scripts

git-svn-id: https://svn.mcs.anl.gov/repos/exm/sfw/turbine/trunk@13888 dc4e9af1-7f46-4ead-bba6-71afc04862de
Add test for blob read.  Fix for blob_read.

git-svn-id: https://svn.mcs.anl.gov/repos/exm/sfw/turbine/trunk@13889 dc4e9af1-7f46-4ead-bba6-71afc04862de