On screens < 90em (approximately 1600px with default font size) wide,
the `Owner`, `Branch`, `Assignee`, and `Project` sections should
overflow with ellipses.
`Project` is handled as a special case -- because most long project
names usually resemble a directory structure, they are truncated to just
the last two parts of the path, with ellipsees appearing before the
leading slash.
Bug: Issue 4552
Change-Id: Icf882cbcecb741fb9e46141a1fa88f5987a3e674
e420236caa