Make "Dnn" and "Tnn" match case-insensitively in the "attach" dialog
Summary: These patterns are hard-coded, allow them to match case-insenstiviely.
Test Plan: Typed "d3" and "D3", got the right object in the attach dialog.
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T1253
Differential Revision: https://secure.phabricator.com/D2511