Add support for deleting user keys to SSHClient.

Review Request #3461 — Created Oct. 27, 2012 and submitted — Latest diff uploaded

Information

Review Board
release-1.6.x

Reviewers

Add support for deleting user keys to SSHClient.

This allows SSHClient to delete a user key. It provides a
delete_user_key function on SSHClient and SSHStorage. This can be used
to provide a UI for deleting a user key.

This UI doesn't exist in Review Board yet, but will be easy to wire up
at some point.
Unit tests pass.