TESTS: Fix quick-test to trap errors where quick-test Red & Red-System tests fail and produce no output
FIX: missing function context pointer restoration on EXIT/RETURN.
FIX: issue #411 (Semi-random compile crash), new attempt at working around this Rebol internal heisenbug.
FIX: relative path handling

Properly support relative paths in explicit output paths (-o) in Red's
compiler (red.r).

Properly support relative paths for input sources and output paths in
Red/System's compiler (rsc.r).

Thanks to Kaj de Vos for bringing this issue to attention.
TESTS: additonal Red 'INSERT tests