This will ultimately be a member of a list of descriptors and
their handler functions on which we need to select() in the
main loop.
o Make struct physical into a `sort' of struct descriptor.
This structure contains the asynchronous state of the physical
link.
Unfortunately, just about every .h file is included in every .c
file now. Fixing this can be one of the last jobs.
This structure will eventually contain a list of NCPs (currently
only IPCP is supported) and a list of physical `struct link's.
It will also derive from a struct link itself.
Make ModemTimeout() static - it's way to dangerous to be called
from outside !
Bump version to 1.9. Our first MP release should be 2.0.
