Add support for live data subscription via Device::subscribeLiveData() and
Device::unsubscribeLiveData(). The live data API can be used to subscribe to
individual "signals", a full list of which can be found in LiveDataValueType.
Because there is now more than one "product name" per device
type, we have a concept of a "generic product name" which
singularly maps onto a device type.
This change comes with a few small breaking changes within
the C++ API:
DeviceType::GetDeviceTypeString has been renamed to
DeviceType::GetGenericProductName to denote that
the returned value is not device specific and
device->getProductName() is preferable.
The member function DeviceType::toString has been renamed
to DeviceType::getGenericProductName for the same reason.
The DeviceType std::ostream& operator<< has been removed
to avoid accidental use of the generic product name.