Fixes #3445 : Clean classes expression in rpmPackageInstallation
Fixes #3446 : read data from an external file for rpmPackageInstallation
Refs #3446 : use readstringarrayidx rather than readstringarray
Merge pull request #83 from ncharles/ust_3444/dev/3446_read_data_from_external_file

Ust 3444/dev/3446 read data from external file