Begin making macro files more human-readable

All macro files are prepended with macros so that they go together in
alphabetical order. If WinCNC supported it, I would use a folder.

They have a .mac extension so they go together in filetype view.
remove m51 and m52 commands which were commented out and missing macro files
rename more macros
some comments
.mac should be lowercase
change drop_tool -> stow_tool
make macro names noun_verb so they group with similar macro files
more macro renaming as I gain domain knowledge
add a silly background
remove old (and potentially dangerous) macros
rename warmup and sweep macros
fix some macro typos
add various todos and notes
start messing with the interface