Set the first weekday based on the locale when the default profile runs.

This is something that has previously happened while setting up default content,
except it was set on portal_calendar. I think it makes more sense here.

I also switched the custom import step registration to ZCML.
only set first_weekday if it hasn't been set yet; add test
remove old cmf permisson. its defined in Products.CMFCalendar anyways. products which need this, should depend on it.
merge pull-request #111