Tweaks to support compiling under Linux

Hi Jules,

I've made a few tweaks to the Makefile to get the code to compile on my Linux box.  This was mainly getting the Tools to compile locally rather than relying on your pre-built binaries in the repo.  I also took the opportunity to tidy up some of the intermediate and output files.  Feel free to merge all, some, or none depending on what seems useful to you!

Michael

Removed prebuilt tool binaries
Added rules to build tools locally
'make clean' now removes more intermediate files
obj/ directory added under git, and objNTSC/ cleaned up
Removed output files