Style fix and update paper number to N3513.

Finish up string_ref for the midterm mailing. N3511.

Commit the initial version of the range-arguments proposal, N3456.

This proposal adds a Range&& argument to all container methods that took
initializer_lists, and defines the Range concept that such arguments must
follow.

Commit the initial version of the string_ref proposal, N3442.

This version was aimed at a TS, so didn't change any existing types.

Tweaks.

Add document number N3337 for 2012 pre-Spring mailing.