log: implemented log_file logging target with per-user/per-session support

         It will check that ip address of tunnel is not in range of clients ip addresses.
         This will avoid kernel softlockups due to loopback occured.

radius: implemented PAP authorization
radius: implemented IP assigning
triton: implemented userspace context switching
and other stuff

ipcp: set addresses and bringing up interface

Merge branch 'accel-pptpd' of ssh://accel-pptp.git.sourceforge.net/gitroot/accel-pptp/accel-pptp into accel-pptpd

Merge branch 'accel-pptpd' of ssh://accel-pptp.git.sourceforge.net/gitroot/accel-pptp/accel-pptp into accel-pptpd

fixed auth type selection when configure-nak received

implemented IPCP IP-Address configuration option

fixed auth type selection when configure-nak received

implemented IP-Address configuration option

using dynamic ppp layers instead of hard coded, but signal transition/handling (up,down,open,close) not fully elaborated