beaker-wizard: escape metachars in Makefile echo statements

Bug: 1165754
Change-Id: Ic6c5c782156cf8dffdf30c651ef3a0d6dc58fddb
beaker-wizard: exclude RHEL4 and RHEL5 from new tests by default

Bug: 1131429
Change-Id: Iae112a2730d33d4f9cc9883af8b89abe140caf0e