#17: changed our Prop.conjugateVerb to use the Lexicon.Feat datatype
instead of our Tense and Person datatypes
since we will get the Lexicon.Feat objects when analyzing a given verb in a given arbitrary complex sentence using P.prs

also commented out all generated words in Lexicon.hs besides the ones starting with a for faster loading during development. (#18)
#19: added number :: Lexicon.Feat argument to Prop.conjugateVerb

created unit tests for all 24 cases
adapted the unit testing framework I developed for PS3

Closes #19.
#14: added back the ability of running multiple unit test suites as described in #20