Adding pppd:
* pppd/Makefile-user: New, copied over from libnetworking/pppd/example.
* pppd/README: New, copied over from libnetworking/pppd/example.
* pppd/init.c: New, copied over from libnetworking/pppd/example.
* pppd/netconfig.h: New, copied over from libnetworking/pppd/example.
* pppd/ppp.conf: New, copied over from libnetworking/pppd/example.
* pppd/pppdapp.c: New, copied over from libnetworking/pppd/example.
* pppd/system.h: New, copied over from libnetworking/pppd/example.
* pppd/pppd.options: New, copied over from libnetworking/pppd/example.
* pppd/Makefile.am: New, converted to automake from Makefile-user.
* pppd/.cvsignore: New.
