Use mchain API to work with mbuf chains.
Do not depend on INET and IPX options.
Allocate ncp_rq structure dynamically to prevent possible stack overflows.
Let ncp_request() dispose control structure if request failed.
Move all NCP wrappers to ncp_ncp.c file and all NCP request processing
functions to ncp_rq.c file.
Improve reconnection logic.
Misc style fixes.
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot). This is consistant with the other
BSD's who made this change quite some time ago. More commits to come.