Whenever

-------------------

- Fix but in ``ZonedDateTime`` ``repr()`` that would mangle some timezone names
- Make ``disambiguate`` argument optional, defaulting to ``"compatible"``.

**Rationale**: This required parameter was a frequent source of
irritation for users. Although "explicit is better than implicit",
other modern libraries and standards also choose an (implicit) default.
For those that do want to enforce explicit handling of ambiguous times,
a special stubs file or other plugin may be introduced in the future.

- Various small fixes to the docs

-------------------

- Add ``Date.days_[since|until]`` methods for calculating the difference
between two dates in days only (no months or years)
- Improve docs about arithmetic rules for calendar and time units.

-------------------

**Fixed**

- Ensure docstrings and error messages are consistent in Rust extension
as well as the pure-Python version
- Remove ondocumented properties ``hour/minute/etc`` from ``Instant``
that were accidentally left in the Rust extension.
- ``exact_eq()`` now also raises ``TypeError`` in the pure Python version
when comparing different types.

-------------------

**Added**

- Make ``from_py_datetime()`` on ``Instant``/``OffsetDateTime`` less pedantic.
They now accept any aware datetime
- New ``Date.today_in_system_tz()`` convenience method

**Fixed**

- Parsing UTC offsets with out-of-range minute components (e.g. ``06:79``)
now raises the expected parsing failure.
- Note in ``parse_rfc2822()`` docstring that it doesn't (yet) validate the input,
due to limitations in the underlying parser.

-------------------

- Fixed ``format_rfc3339()`` docstrings that incorrectly included a ``T`` separator.
Clarified that ``T`` can be added by using the ``format_common_iso()`` method instead. (185)

-------------------

**Added**

- Added ``YearMonth`` and ``MonthDay`` classes for working with year-month and month-day pairs

**Fixed**

- ``whenever.__version__`` is now also accessible when Rust extension is used