Make VariableParser into a static only class.

Instead of having new instances of VariableParser created, and thus wrapping
a Map<String, Variable> in a very inelegant way, simply have a single method
that actually does the VariableParser work, and directly returns the Map.
Also ensure all tests + Matlab continue to work, and tighten up some extra
imports and Matlab output in affected areas.

git-svn-id: https://groke.mcmaster.ca/svn/grad/colin/branches/TableTool_javization@10846 57e6efec-57d4-0310-aeb1-a6c144bb1a8b