Add an input widget with a copy text link

Review Request #8980 — Created May 31, 2017 and submitted — Latest diff uploaded

Information

Djblets
release-0.10.x
0148e9d...

Reviewers

Sometimes it makes sense to have a text widget that the user will want
to easily copy data from, such as with generated authentication tokens,
etc. The CopyableTextInput is a specialized TextInput widget that
renders a link to copy the text from the associated field.

Using this with an upcoming change for OAuth forms.