Set the value of LSST_HOME in the loader scripts at execution time. This is one of the ingredients
necessary for making the stack relocatable.

The loader scripts determine the directory where they are located and use that path as the value of
the LSST_HOME environmental variable, if not already set.

Please note that ksh is not supported with EUPS v1.3.0 so the generated loader script loadLSST.ksh
prints an error.
Merge branch 'relocate' into develop
Merge branch 'develop'