Adding machine dependent SLIP routines for UART0.
Adding machine dependent SLIP routines for UART0.

bluerover/6lbr,arurke/contiki,arurke/contiki,bluerover/6lbr,MohamedSeliem/contiki,arurke/contiki,arurke/contiki,MohamedSeliem/contiki,arurke/contiki,MohamedSeliem/contiki,MohamedSeliem/contiki,arurke/contiki,MohamedSeliem/contiki,bluerover/6lbr,arurke/contiki,MohamedSeliem/contiki,bluerover/6lbr,bluerover/6lbr,MohamedSeliem/contiki,bluerover/6lbr,bluerover/6lbr