Move some forgotten Matlab specific code into its parser.

The code to find the operation for a given text string was hidding in the
*Operation enumerations.  Move this code into MatlabParser, as it isn't
reusable as many languages use different symbols.

git-svn-id: https://groke.mcmaster.ca/svn/grad/colin/branches/TableTool_javization@10849 57e6efec-57d4-0310-aeb1-a6c144bb1a8b