Remove constructors we don't want:
gst_date_time_new_ymd_h() because we don't want to
support hour-only for now;
gst_date_time_new_ymd_hm() because we don't want to
add constructors with time info where the caller doesn't
have to think about what timezone the time is in.
Lots of compulsive clean-up. Docs fixes. Replace
has_minute() and has_hour() with has_time().
In order to deserialise and re-serialise dates and date times
from tags properly, we need to be able to express partial
dates (e.g. YYYY or YYYY-MM) and date times.
We only support partial date times where all the more
significant fields above the first unset field are set
(e.g. YYYY-00-DD is not supported).
Calling _get_foo() when foo is not set is not allowed
any more, callers need to check which fields are set
first.
https://bugzilla.gnome.org/show_bug.cgi?id=677757
Fix returning of timezones on systems with gdatetime
to use floats on the math expression to avoid
truncating the fractional part.
Also adds a test for covering this case.
Adds 2 variants for the gst_date_time_from_unix_epoch function,
one for UTC and another for local time.
API: gst_date_time_new_from_unix_epoch_utc
API: gst_date_time_new_from_unix_epoch_local_time
Fixes#653031https://bugzilla.gnome.org/show_bug.cgi?id=635031
