Automatically generate Entity repositories

[seanjparker]

When adding new entities you also need to create a new Repository class which extends the TransactionalRepository. All of the classes are pretty much the same:

@provide(ApplicantRepository)
export class ApplicantRepository extends TransactionRepository<Applicant> {
	public getRepository(): Repository<Applicant> {
		return super.manager.getRepository(Applicant);
	}
}

It would be much nicer to have a uniform way of representing the typeorm repositories.

Note: We need the shim to extend TransactionRepository since #68.