clean: Use CLEAN_dotfile
clean: Get rid of CLEAN_reqs, just depend on dotfile
everything: Nuke EVERYTHING_reqs and depend on dotfile
Don't depend on out module, it comes for free
makery: Add MAKERYIGNORECACHE
run: Get rid of _reqs and use _dotfile
PROJ_Rule(): Allow commandless rules that just add dependencies
build: Get rid of _target and _reqs, just use _dotfile
dotfiles act phony by default, no need to declare
doxygen: Get rid of _target and _depends, just use _dotfile
test: Get rid of _target, just use _dotfile
run: Factor out runnable