Give Phragment a sort of tetris block thing as a title glyph

Summary:
Fixes T11679. This application is probably vanishing into the aether eventually, but stop it from fataling for now.

Here's the glyph: ▛

It's like a fragment of a block of file data! Right? Obviously.

Test Plan: Visited /phragment/ with glpyhs on, saw the glyph.

Reviewers: chad, avivey

Reviewed By: avivey

Subscribers: avivey, hach-que

Maniphest Tasks: T11679

Differential Revision: https://secure.phabricator.com/D16588