Compare timeSpecs when comparing incidences for equality
setDtStart()
compares the timeSpecs of the old and new start dates so
that it can distinguish "floating" date-times from date-times with
defined time zones when deciding whether the incidence is dirty.
setDtDue()
and setDtEnd()
do likewise. See commit 322782ce.
For the same reasons, the various equals()
should also compare
timespecs of those fields.
I also renamed LOCAL_TZ
because I found it a bit unclear, given that I'm dealing with
LocalTime
timespecs and my local timezone isn't Paris.