Fix glitch with blame.
Fix glitch with blame.

Rendering the changeset for the XHR response didn't set the `text`
parameter of `generate_template_fragment`. Add a default of `False`,
consistent with the rest of the `Chrome` API.



git-svn-id: 0d96b0c1a6983ccc08b3732614f4d6bfcf9cbb42@15452 af82e41b-90c4-0310-8c96-b1721e28e2e2

rbaumg/trac,rbaumg/trac,rbaumg/trac,rbaumg/trac