Ical

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

Fixes:

- Successfully test with pypy and pypy3. [gforcada]

- Minor documentation update. [tpltnt]

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

New:

- Updated components description to better comply with RFC 5545.
Refs 183.
[stlaz]

- Added PERIOD value type to date types.
Also fixes incompatibilities described in 184.
Refs 189.
[stlaz]

Fixes:

- Fix testsuite for use with ``dateutil>=2.5``.
Refs 195.
[untitaker]

- Reintroduce cal.Component.is_broken that was removed with 3.9.2.
Refs 185.
[geier]

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

New:

- Defined ``test_suite`` in setup.py.
Now tests can be run via ``python setup.py test``.
[geier]

Fixes:

- Fixed cal.Component.from_ical() representing an unknown component as one of the known.
[stlaz]

- Fixed possible IndexError exception during parsing of an ical string.
[stlaz]

- When doing a boolean test on ``icalendar.cal.Component``, always return ``True``.
Before it was returning ``False`` due to CaselessDict, if it didn't contain any items.
[stlaz]

- Fixed date-time being recognized as date or time during parsing.
Added better error handling to parsing from ical strings.
[stlaz]

- Added __version__ attribute to init.py.
[TomTry]

- Documentation fixes.
[TomTry]

- Pep 8, UTF 8 headers, dict/list calls to literals.
[thet]

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

- Fix ``vPeriod.__repr__``.
[spacekpe]

- Improve foldline() performance. This improves the foldline performance,
especially for large strings like base64-encoded inline attachements. In some
cases (1MB string) from 7 Minutes to less than 20ms for ASCII data and 500ms
for non-ASCII data. Ref: 163.
[emfree]

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

- Creating timezone objects from VTIMEZONE components.
[geier]

- Make ``python-dateutil`` a dependency.
[geier]

- Made RRULE tolerant of trailing semicolons.
[sleeper]

- Documentation fixes.
[t-8ch, thet]

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

- Add missing BYWEEKNO to recurrence rules.
[russkel]