Implement ISO 8601 calendar date object.

This will handle parsing the calendar date formats defined in
ISO 8601 and producing a datetime.date duck typed object that
can be used to output all the calendar date formats.

Testing for the ordinal and week date formats still needs to
be performed.
Completed ISO 8601 date implementation.

The isodate class can now handle all representations that are
found in ISO 8601 section 5.2.
Started implementation of ISO 8601 time.

The unittest for isotime is compete and the parsing of the
representations is complete.
Added format specification to isodate.

Additional implementation on isotime, but all tests are off
so it is not ready to be used yet.
Added an overall ISO 8601 representation parser.

This parser will be able to break up all ISO 8601 representations
and have each parsed according to date, time, datetime, duration,
or recurring rules. It is strict in that all times must have the
time designator [T] as part of the representation.
Further implementation of isotime.
Fixed errors in fractional minutes and hours.
Completed isotime testing and bug fixing.
Adding isodatetime support that ducktypes datetime.
Continued improvement of ISO 8601 datetime testing.
Added addition tests for date and time.

Note that the email address for Lance Helsten before this
was an incorrect global email. It has been fixed for this
commit.
Store current method before switching to JD.
Added isodatetime and corrected test failures.
Merge branch 'develop'
Integrated isodatetime into vCard.