Reworked polyfill support for Zend\Stdlib\ArrayObject

- Instead of using an autoload file, instead created two separate classes, named
  after the type of support they provide. The file Zend\Stdlib\ArrayObject now
  simply has a conditional in it; based on the condition met, a class_alias() is
  created -- and from then on, that alias will be used for
  Zend\Stdlib\ArrayObject.

- Removed autoload.files entries from composer.json files; no longer necessary.

- One test failure currently in doing a comparison of merged array objects; will
  investigate in a later commit.
Reworked polyfill support for Zend\Session

- Created Zend\Session\Container and Zend\Session\Storage\SessionArrayStorage
  namespaces. Each contains PhpLegacyCompatibility and PhpReferenceCompatibility
  classes. The classes with the same name as the new namespaces each use
  conditionals to execute class_alias() commands in order to perform
  version-specific polyfills.
- Removed compatibility/autoload.php from composer.json autoload.files; no
  longer necessary.
- All tests are running!
Fix failing Zend\Session test under 5.3.3

- bad import
Re-added autoload.php files

- BC measure, so that code referencing these files doesn't break
Renamed compat autoload files and marked as deprecated

- moved autoload.php files into compatibility subdirs where they belong
- marked each with @deprecated annotation
Class stubs to force classmap generation
Trigger E_USER_DEPRECATED in deprecated polyfill autoload files
Simpler polyfill support

- Have a base class that extends a polyfill class
  - makes classmap generation simpler
  - makes typehinting and mock objects simpler
Mark all polyfill bases as abstract

- they are not intended to be instantiated directly; they are intended as bases
  for the typehinted class that uses the polyfills.
Don't need an additional polyfill class for Container

- since the "legacy" class simply extended AbstractContainer, can use
  that as the polyfill
Do not need 5.3.3 polyfill for SessionArrayStorage

- It was an empty extension of AbstractSessionArrayStorage; simply use
  that class as the polyfill
Resolved #3963 #3971 This change adds a new interface: StorageInitializationInterface which is used by SessionArrayStorage to populate the RequestAccessTime.