* Move majorLables to 1st week in the month, for 'week' scale
* next() always adds 1 week to current date
* show 1st week in the month as majorLabel
* Add 'week' to auto-scale
* Update week scale example
* Revert "Move majorLables to 1st week in the month, for 'week' scale"
This reverts commit 52df3c3ac5.
* Correct value of week's minimumStep