importutils: initial release

* Cherry-picked from aa191a583772a77bfd86d8f4d608e7ada2fe613e.

Co-authored-by: Jiri Kuncar <jiri.kuncar@cern.ch>
Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
importutils: Python 2.4 support and test case

* Adds Python 2.4 support to importutils.

* Changes from using glob to regular expression for
  module matching.

* Adds test case.

Tested-by: Tibor Simko <tibor.simko@cern.ch>
importutils: Makefile clean up

* Removes doubly inserted importutils in Makefile.am.