Added code to auto-generate manpages
Added legacy functions to common.c/h

That is rc_getstr() and rc_fgetln() were removed from the
freeradius-client library. They were not even remotely related
to radius.
removed rc_getifname

This was only related to radlogin, but not
even used by it.
bumped lib version number
rc_avpair_tostr: do not depend on strlcat