use interface names "vethOOOOO.ii.ss" and "vethOOOOO.iipss" for veth pairs
(where OOOOO = object id, ii = interface index, ss = hex short session ID)
fixes bug #260 virtual interface names too long
(Boeing r1894)
use "vethA.B.SS" name for veth devices (A = node number, B = index, SS = short session ID)
use "tapA.B.SS" name for tap devices; use "b.A.SS" name for bridge devices
added a SESSION_SHORT environment variable to the default CORE environment
(Boeing r1867)
