Rename the internal bundles

[netsensei]

Detailed description

There's a difference between the bundle (folder) name and the class name. This is very confusing:

OAuthBundle > DataHubOauthBundle
SharedBundle > DataHubSharedBundle
UserBundle > DatahubUserBundle
OAIBundle > DataHubOAIBundle
ResourceBundle > DataHubResourceBundle
ResourceAPIBundle > DataHubResourceAPIBundle

Context

Do we need the 'DataHub' prefix for each bundle? Omitting that would make things more clear and maintainable.