Add virtual tab placeholder for new Product/Content editing

* Re-create the IContent->ContentItemDisplay map so we can add a custom AfterMap event (probably a hack?)
* Check for existence of merchProductKey property before adding tab
* Add virtual tab and property (placeholder for now)
moved shipping history into directive
Updates AuthorizeNet provider to use NuGet package from NuGet.org
removed circular reference on js object
fixed filter on payment history list
Merge pull request #612 from rustyswayne/1.1.1

Updates AuthorizeNet provider to use NuGet package from NuGet.org
removed the variant column from the shipment history.
Merge pull request #614 from bowserm/1.1.0_M224

1.1.0 m224
created and mostly implemented NotificationsApiController.
More work on the SMTP Notifications Gateway Provider
Merge pull request #617 from rustyswayne/1.1.1

More work on the SMTP Notifications Gateway Provider
Merge pull request #615 from bowserm/1.1.1_M252

1.1.1 m252
Bumped Merchello Version to 1.1.1.  Patched GatewayProviderApiController
Merge pull request #618 from rustyswayne/1.1.1

Bumped Merchello Version to 1.1.1.  Patched GatewayProviderApiController
Moved NotificationMessageService back to internal on ServiceContext
Internalized INotificationMessageService
Merge pull request #619 from rustyswayne/1.1.1

Moved NotificationMessageService back to internal on ServiceContext
Readded notifications to merchello tree
Merging
Merge commit 'fetch_head' into Notification