Import gambatte-dev-5.5.0 as wip/gambatte-dev.

Gambatte is an accuracy-focused, open-source, cross-platform Game
Boy / Game Boy Color emulator written in C++. It is based on hundreds
of corner case hardware tests, as well as previous documentation
and reverse engineering efforts.

This is the development version of gambatte.
+gambatte-dev; Enjoy.
gambatte -> gambatte-dev