Similar to gbasm, break the testing into different files for sanity's
sake. This patch also adds a "test" register state which is compared
to the state of the actual CPU registers at the end of the test.
Finally, break the inc and dec tests, but add "ld r8, r8" and "ld dr,
d8" tests.
It's not very good, but it supports all of the options by the
previous far-worse Makefile configure targets, and also now supports
out-of-tree builds.
Also include the relevent updates to the .buildbot script and
.gitignore.
Though not a real register, the operand "(hl)" fits in
better with the 8-bit registers than it does with the
sixteen bit ones. As such, move its definition.
Also, define useful values for the 8-bit operands rather
than arbitrary ones.
