Renames pin_name() from avrpart.c to avr_pin_name() and adds a
(globally visible)declaration in avrpart.h
The function takes an integer argument from the pin-enum in pindefs.h and
converts it to a string. The returned string corresponds to the pin names used
in avrdude.conf.
git-svn-id: svn://svn.savannah.nongnu.org/avrdude/trunk/avrdude@1095 81a1dc3b-b13d-400b-aceb-764788c761c2
