CASA matrix testing fixes

CASA versions are fun. This fixes 2 problems.

First, if a pipeline version can't be deduced from the directory name, we set it to "default". We COULD get it by inspecting within the release version directory and following the pipeline symlink, but even then it would take some regex manipulation to get it, and this only happens for older versions of CASA (pre 6.*). Let's keep it as "default" and not compare those to proper pipeline versions in the pipeline manifests (e.g. 5.6.1-8|default will now match with 5.6.1-8|40896 (Pipeline-CASA51-P2-B)).

Second, CASA likes to use "." and "-" characters interchangeably in both the pipeline manifest and directory names. I've seen 6.1.1-12 in the directory name with 6.1.1.12 in the manifest and 5.6.1-8 in both. We're now ignoring "." and "-" characters when comparing version numbers.