Added another utility method(with unit test) for the low-bandwidth notification type
Added code for LowBandwidth event detection and notification. Yet to implement the remaining part of the hourly script(NodeDown notification)
Fixed minor internal documentation error
Implemented the NodeDown notifier based on the older weather's criteria(Refer to design document for more details)
Integrated the t-shirt script(#9889) functionality with the welcome script in a new 'daily script'; Also added the DataError exception and  check to the onionoo-wrapper