Added a ping interval on the client to ensure that auth tickets do not expire when there's lack of activity.

- This also involved adding a new configuration option 'pingInterval' which can be set via seconds
Added tests to verify that pingInterval behaves correctly with different configuration options in addition to multiple connection starts and stops.
Updated tests to utilize the new ping server signature
Addressed code review comments

- Changing an error message to not be prefixed with "SignalR:" and adding a log for it.
- Added a failsafe to the ping server common utility so that if there is no transport defined we instantly reject the deferred (essentially nooping).
- Removed the connection stop from a ping interval fail.
- Modified the ping interval fail to use the new js error resources.
- Removed the test that ensured that a failed ping interval would stop the connection.

Updated errors to be signalr transport errors.

Flowed the ping server fail to the connection error