Remove unused definitions

These are board specific, and since they're not even used, get rid of
them.
Enable "no optimization" builds

This requires some layout change to make room.
Rename build output directory

The architecture is part of the directory hierarchy already
More MSVC support

The MS assembler version of the X64 entry point is a bit limited
compared to the GCC version (eg. no Pcd support), but it works for now.

Then there are a number of changes to accomodate the MSVC compiler.