This matches the implementation provided by Java NetworkTable, with the
exception that the subtable is not provided (because it's not a value).
The listener still can get access to the subtable by calling
source->getSubTable(key).
- Missing header file callouts in some cases (library deltas)
- Lack of support for auto parameters in lambdas
- Defining of ERROR by windows.h
- Dispatcher::Connection needs a move constructor (default not generated)
- Need explicit enable_if on std::string move template in Value to avoid trying to move const char[] (string literal)
- Compile flags
