bradfitz/http2 — pull request #24 by DanielMorsing (2014-12-14 13:13:36+00:00)
Title: strengthen priority tree code and add tests

The priority tree codes has been strengthened to handle some new
corner cases.

- Handle setting the parent to itself.
- Handle exclusive reprioritization to the root stream.
- Handle reprioritization to stream dependent of stream being
reprioritized.

In addition, split out the adjustment function so that it can be
tested independently of the serverConn and add tests.