Added automatic detection of system libraries to 5l.
Added automatic detection of system libraries to 5l.

R=rsc
APPROVED=rsc
DELTA=83  (73 added, 3 deleted, 7 changed)
OCL=29276
CL=29382

tav/go,tav/go,tav/go,tav/go,tav/go,tav/go,tav/go