Date field with "No Timezone Handling" applies wrong timezone in rrule on until, exdate and rdate

My problem seems similar to this closed issue #1014664: Repeat Until Issue but it doesn't look like that was committed and I'm not sure it's correct for my situation.

I'm using a date field with repeating configured to use "No timezone handling". The Site timezone is set to New York and users set their own timezone. I discovered the problem mostly on events with DAILY repeats because the last day would display as the next day, ie. it repeats daily ending on OCT 27 but when the date is output in views and field output in the node then it shows as going until OCT 28. Also, for excluded dates I set OCT 24 but the output for the repeating rule read, "excluding OCT 23". The output on these is only wrong for users with their timezone, ie. Los Angeles, set to something different than the Site timezone. When I check the database I see the following rrule based on those dates:

RRULE:FREQ=DAILY;INTERVAL=1;UNTIL=20171028T045959Z;WKST=SU
EXDATE:20171024T050000Z

I think those times should not be adjusted for timezone. The UNTIL time should be set to 23:59:59 of the final date and EXDATE time should be 00:00:00 of the date. Also, with the field configured with Timezone handing set to "No timezone handling" (a.k.a. 'none' in the date API) then the timezone is defaulting to "date_default_timezone()" which returns the Site's setting for the timezone instead of the field's setting of 'none' which should set everything to 'UTC'.

The fix in the attached patch touches both, date_api and date_repeat. I have not tested this with other date field configurations. Does timezone need to be applied to these until/exclude/add dates for other use cases?

This patch only fixes the problem for data entered from now but does not correct any old data. It looks like there is a bit of a mess in the old data because those old dates will need to be rolled back the proper number of hours (daylight savings is applied to some).