add debug logging in modpath_extensions_for
fix path_to_top_of_module_tree to consider multiple paths to the top of the module tree
add unit test for checking load statements in imkl module under HierarchicalMNS
fix added unit test for Tcl-based module tools: don't use test modules that unload recursively and make 'purge' fail
fix broken tests
cleanup in GCC test module
fix typo in GCC test module
fix remarks
Merge pull request #1047 from boegel/fix_path_to_top_of_module_tree

fix path_to_top_of_module_tree to consider multiple paths to the top of the module tree