[erlang-patches] week number support

[Imre Horvath]

Hi Niclas! Hi OTP Team!

I have added the missing support for calculating the week number to the
calendar module in the stdlib application.

This implementation conforms to the ISO 8601 hence the name iso week number.

Implementation is added, test suit for calendar extended with test case and
also the documentation of calendar has been updated.

Testing was successful.

Please fetch!

git fetch git://github.com/imrehorvath/otp.git iso_8601_erl

Best regards,
Imre