CRM_Utils_Hook - Fire Symfony event dispatcher for hook_post and hook_pre.
CRM-14727 - Fire case-change events which include Civi\CCase\Analyzer.

Notes:
 * The key underlying event (hook_civicrm_post) is already fired, but you
   have to bind to it a couple different ways (eg listen for a change to an
   "Activity" and then check the "case_id").
 * A key goal is to allow multiple event-listeners to use the same instance of $analyzer.
 * One can bind to the case-change event in one of three ways: (a) hooks, (b) event-dispatcher, (c) CiviCase XML listeners.
api_v3_CaseTest - Move setup/teardown to CiviCaseTestCase
CiviCaseTestCase - Allow specifying the XML file. Allow hook-XML to override core-XML.
CRM-14727 - Implement Civi\CCase\SequenceListener
CRM-14727 - Move $isActive from SequenceListener to Events

When a case-change listener makes another change to a case, we don't want to
refire all the case-change listeners.  $isActive helps avoid that (infinite)
recursion.

This commit has two important qualities:

 1. The code is simpler. There's a single set() and single unset().
 2. Developers of new case-change listeners don't need to worry
    about recursion problems -- it's handled centrally.
CRM-14727 - crmCaseType - Use the "<sequence>" tag instead of "<pipeline>" tag
Merge pull request #3368 from totten/master-case-sequence

CRM-14727 - Implement activity pipelines/sequences