Gradescope Autograding for CS19!

The result-processing project handles converting from pyret's output to the format gradescope expects. When rebuilding it, make sure to copy the executable it produces to gradescope/gradescope_report.

To prepare the autograder on gradescope, place wheats, chaffs, tests, and stencil files in their respective directories, and zip the contents of the gradescope directory for uploading