Defaulting Mode to Sandbox

- Eliminate the need to define config for mode
Renaming Namespaces and Organizing Classes

- Updated OpenId classes to be in API namespace
- Updated PP Naming Convention to PayPal Naming Convention
- FormatConverter Class got its own namespace
- Handlers are grouped in Handler namespace
- Samples and Tests Updated Accordingly
Merge branch '1.0.0-beta' of https://github.com/paypal/PayPal-PHP-SDK into 1.0.0-beta

Conflicts:
	lib/PayPal/Handler/OauthHandler.php
	lib/PayPal/Handler/RestHandler.php