Expand recurring event enh

[muddjones]

1. Added support for day recurrence (i.e. BYDAY=3TU) :: [lines 36-44, 95-100]
2. Break out of 'for' loop once date is found :: [line 115]
3. Once first date in recurring series is found and newStart and newEnd are reset, roll back to the first of the month of newStart and set newEnd accordingly :: [lines 151-158]
   NOTE: This change was added because test cases like this were failing:
   I correctly received an event on 11/04/2019, but since 1 month was added to this start date, the next month started looking for "first monday" on 12/04/2019 and returned 12/09/2019 when it should have returned 12/02/2019.

TEST CASE EXAMPLE:
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20191104T090000
DTEND;TZID=America/Los_Angeles:20191104T100000
RRULE:FREQ=MONTHLY;BYDAY=1MO
DTSTAMP:20191023T175925Z
UID:6uvrlpou5dsso6hnng6p65es41@google.com
CREATED:20191021T154144Z
DESCRIPTION:
LAST-MODIFIED:20191021T220941Z
LOCATION:
SEQUENCE:1
STATUS:CONFIRMED
SUMMARY:Test Monthly First Monday
TRANSP:OPAQUE
END:VEVENT

Attached is a test file I used to verify my changes in multiple scenarios.
multiRecurrExamples.ics.txt

[apognu]

Existing tests are failing when I try and merge this. Also, could you write a test case validating recurrence expansion for this?