CRM-12427 Fixes and patch

Applied patch with additional modifications & improvements:

- Improved error display for mixed status. For example if out of 10 messages, 3 failed, it only displayed failure counts.

- Mass sms got broken because as it now tries handling bounces for sms, and bounce handler is not customized for sms workflow. Its a good news as well. I have made the code to skip processing bounce for sms for now.