Add utility functions for building e-mail addresses.

Review Request #8398 — Created Sept. 14, 2016 and submitted — Latest diff uploaded

Information

Djblets
release-0.9.x
3dcbefe...

Reviewers

This adds a couple of small utility functions that take a user (or a
user's information) and constructs an e-mail address intended for use in
a To/CC/BCC field. These are ports from the existing e-mail code that
lives in Review Board, and will be used and improved upon in some
upcoming e-mail work in Djblets.

Unit tests pass.