PHP - DocumentRoot logic (optional php/ directory)

https://trello.com/c/AK1v0o4x - origin_cartridge_card_57
https://trello.com/c/XdJdVHU9 - origin_cartridge_card_138

PHP's Apache DocumentRoot is selected based on the existence of a common
public repo directory in the application code in the following order:
1. php/          # for backward compatibility with OpenShift Origin v1/v2
2. public/       # Zend Framework v1/v2, Laravel, FuelPHP, Surebert etc.
3. public_html/  # Apache per-user web directories, Slim Framework etc.
4. web/          # Symfony etc.
5. www/          # Nette etc.
6. ./            # Drupal, Wordpress, CakePHP, CodeIgniter, Joomla, Kohana, PIP etc.

Add following common library repo directories to PHP's include_path:
- lib/
- libs/
- libraries/
- src/
- misc/
- vendor/
- vendors/

Simplify PHP's Template Repository Layout to:

    index.php         # Template PHP index page
    .openshift/       # Location for OpenShift specific files
        action_hooks/ # Action Hooks
        markers/      # Marker files
        pear.txt      # List of pears to install
        pecl.txt      # TODO: For future PECL support https://trello.com/c/Ja9IcFIb

Other features/fixes:
- implement Apache DocumentRoot & Access Controls cucumber tests
- deprecate deplist.txt in favor of .openshift/pear.txt
- add Directory Layout, DocumentRoot & include_path oo_cartridge_guide documentation
- php bin/control - move duplicated lines to pre_start_httpd_config
- prevent Apache from serving the following internal files/dirs when
  root repo dir is selected as DocumentRoot:
  - $OPENSHIFT_REPO_DIR/.openshift/
  - $OPENSHIFT_REPO_DIR/deplist.txt
- fix PHP's openshift.conf file ownership:
  - migration: upgrade existing apps
  - fix cucumber tests for all *.conf files
- remove obsolete php/ dir checks from cucumber test
- remove obsolete health checks from PHP and Perl