Makefile tweaks

[sjmulder]

• Respect system CFLAGS by adding to it, rather than overriding.

• Use built-in inference rules for compilation. It's shorter but technically the defaults may be better suited to the system or build environment.

• Don't override default optimization level. Except in specific cases the system wide configuration should be respected.

  • Mark 'clean' as a phony target, which is to say that it's not a file target so the existence of a 'clean' file doesn't satisfy the target.

All matters of taste though so no hurt feelings if you disagree!

[tenox7]

I like it as it's much shorter. Thank you!