Announcing gpioplus

[William Kennington]

Yet another c++ wrapper in a series of changes I've been working on to
make ergonomic c++ abstractions for commonly used library functions.
This project intends to provide a simple c++ interface around the
existing linux userspace gpiolib syscalls. The functionality is
complete and the tests cover the entire interface.

As usual, please let me know what you think of the project. It currently
resides at https://github.com/wak-google/gpioplus. This should find
a new home at https://github.com/openbmc/gpioplus if it receives
good feedback.

Thanks,
William