main.c : drop the giant usage text now that we have a man page.
git-svn-id: svn://svn.savannah.nongnu.org/avrdude/trunk/avrdude@42 81a1dc3b-b13d-400b-aceb-764788c761c2
more modular pieces.
Also, accept command abbreviations as long as they are not ambiguous.
git-svn-id: svn://svn.savannah.nongnu.org/avrdude/trunk/avrdude@38 81a1dc3b-b13d-400b-aceb-764788c761c2