Provide suggestions for htaccess under PaaS

- Many PaaS solutions, including phpcloud.com and OpenShift, use an
  Apache Alias directive, which can lead to problems with rewrites. This
  changeset provides some comments showing a typical solution to this
  issue.

git-svn-id: http://framework.zend.com/svn/framework/standard/trunk@25180 44c647ce-9c0f-0410-b52a-842ac1e357ba