Revert "Reduce number of shift/reduce conflicts in matrix parser."

This reverts commit 8e0e187b82fab6c95eba27806bbedf5c9a934bd1.
Add a BaseParser object to calm RPython.
Get SMXF and matrix parser translating correctly.
Support reading source files from stdin.
Add donor cell source file and matrices.
Add support for reals using scientific notation.