Updated REST and SOAP API's to support External Authentication.

- Added a :require_user option to User.authenticate
- Added :timeout option to MiqTask.wait_for_taskid
- Updated REST API to pass HTTP Env and option to User.authenticate
- Updated Appliance Console to extend the Apache External configuration
to be REST and SOAP API aware.
- Properly unconfiguring HTTPD application from appliance console.
- Added REST API and SOAP :authentication_timeout config, both
default to 30 seconds
@abellotti The timeout value should be set closer to where it is used since we can return from this method before we reference the variable.