Added cache of original values, so that str(rrule) works.
Added cache of original values, so that str(rrule) works.

pganssle/dateutil-test-codecov,pganssle/dateutil-test-codecov,abalkin/dateutil,sprymix/python-dateutil,jenshnielsen/dateutil,mjschultz/dateutil,Bachmann1234/dateutil,sprymix/dateutil,abalkin/dateutil