Implement LINALG

[chakravala]

If anybody would like to try implementing a new feature from this package, it is not so difficult to do by using the pasegen function generator and then making a pull request. Typically, all that is needed is to add the :function_name to the list of symbols and perhaps an extra function definition to handle multiple dispatch or special cases more efficiently. Documentation, examples, and tests also needed.

Upstream docs: http://www.reduce-algebra.com/manual/manualse127.html