Move lingering "Aphront" classes out of libphutil
Ref T13395. These classes have no callers in libphutil or Arcanist; move them to Phabricator.
(HTTPSFuture also parses HTTP headers, but has a builtin parser as part of a more complicated stream parser. Possibly, it should not.)
Test Plan: Grepped libphutil and Arcanist for affected symbols.
Maniphest Tasks: T13395
Differential Revision: https://secure.phabricator.com/D20974