Use dispatch_group around connection initialization
Use dispatch_group around connection initialization

- SFTP operations are kicked off with dispatch_group_notify
- Also changed self to weakSelf where appropriate

Issue #3

dleehr/DLSFTPClient,dleehr/DLSFTPClient,brittonmobile/DLSFTPClient,brittonmobile/DLSFTPClient,dleehr/DLSFTPClient,brittonmobile/DLSFTPClient