Wrote a function to read in data files where only the inputs/outputs and frequencies have been specified.
Also wrote two functions to apply markedness or faithfulness constraints to all the forms in the tableau.
***This is underspecified at the moment, as we are waiting for the regular expression team to define our constraint format***
***Assumes two things:
          1. constraints come in lists of only faithfulness or only markedness
          2. faithfulness constraints apply to a UR, SR tuple
***
Updated documentation in megatableau.