Phabricator event timeline removed

Summary: Removed related files and references

Test Plan: Crossed my fingers

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin, AnhNhan

Maniphest Tasks: T2003

Differential Revision: https://secure.phabricator.com/D5744

Conflicts:
	src/__phutil_library_map__.php
	src/infrastructure/storage/patch/PhabricatorBuiltinPatchList.php