INSTALL: Trollius is for Python <= 3.2, not just Python 2.7. Refs #1647.
tests: In test_get_async_threadsafe, if can't import asyncio, then import trollius as asyncio. Refs #1647.
CHANGELOG: Added bug fix for Trollius 0.3. Refs #1647.
ThreadsafeFace: Fix doc comment: Trollius is for Python <= 3.2, not just Python 2.7. Refs #1647.
Merge branch 'issue/1647-trollius-import-asyncio'. Refs #1647.
http://redmine.named-data.net/issues/1647