Rewrite the hwstub library in C++, with a clean and modular design.
The library was designed from the ground up to be aware of multithreading
issues and to handle memory allocation nicely with shared pointers.
Compared to the original library, it brings the following major features:
- support for JZ boot devices, it is very easy to add support for others
- support for network transparent operations (through sockets): both tcp
and unix domains are support
Change-Id: I75899cb9c7aa938c17ede2bb3f468e7a55d625b4
