Add a setting to control the start day of the week

Problem/Motivation

It'd be very useful to be able to control which day of the week is considered "first" for the month and week calendar views.
Monday vs. Sunday or Saturday is the obvious case, but some sites might need their calendar views to consider each week starting on Wednesday or something.

Proposed resolution

Add a view display setting and propagate it to the fullcalendar JS library to control first day of the week.
We should allow all 7 choices, and default to Sunday to maintain current behavior.

Remaining tasks

Figure out how the underlying JS library handles/supports this.
Add the setting to the view display.
Propagate the value to the JS.
Upload patch.
Review/test.
Commit.

User interface changes

New views display setting to control day-of-week (dow) to start from.
Different UI for end-users of the calendar if the view is configured to use this.

API changes

None.

Data model changes

None. Storage for the display setting is handled by views itself.