pptp for Nokia 770

Release 1

Must replace kernel (pptp needs kernel ppp_mppe, which can be compiled as
module, but requires kernel crypto which can't be a module). Included kernel
is the same as the one in 2006.26, but with ppp_mppe compiled in kernel.
Write to device with:
   flasher-2.0 -k zImage-su-18-200626-mppe -f

pptp binary needs to be copied to somehwere in the path.

Needed config files are:
   /etc/ppp/pap-secrets
   /etc/ppp/chap-secrets
   /etc/ppp/options.pptp
   /etc/ppp/peers/bgu

If you want to connect to BGU network, just copy the files from this archive,
and replace all occurrences  of myname and mypass with your name and password,
accordingly.

For other networks, probably some more changes are necessary. It is probably
easeier to setup pptp on some laptop or desktop computer, and copy the config
files.

Finally, to connect to the pptp server, first establish the low level network
(WIFI, GPRS, or usb networking), and then run 

   pppd call bgu


Bugs:
- Sometimes default route is not setup correctly and needs to be changed by
  hand.
- DNS is not updated by pppd, so needs to be changed by hand (if it is
  different from the one provided by the low level network). This is also
  problematic since I don't know how to get dnsmasq to accept the change, so I
  do this by overwriting /etc/resolv.conf.

Missing features:
- Establish pptp tunnel automoatically when connected to correct low level
  network.
- Configuration tools.

