Consolidate duplicated build tools and headers

[pinobatch]

Several files in <project name>/tools are duplicated between projects, as is <project name>/src/hardware.inc. The latter should be amenable to RGBASM's -i switch to add an include path. So do the same thing I did when combining NES, GB, and GBA packaging in 240p Test Suite: move anything common to several projects into the common folder.