RepositoryProvider.getProvider(
IProject project)
Returns the provider for a given IProject or null if a provider is not associated with
the project or if the project is closed or does not exist.
RepositoryProvider.getProvider(
IProject project,
String id)
Returns a provider of type with the given id if associated with the given project
or null if the project is not associated with a provider of that type
or the nature id is that of a non-team repository provider nature.
