When vw exitcode != 0, output the stderr file to the user since the
actual reason for the failure is likely in there.
Errors should go to stderr
Show 'vw' run stderr to user in case its exit status is != 0
Add debugging level-4 to RunTest fuzzy diff.
More detail in debugging
Errors should go to 'cerr' not to 'cout'
Merge branch 'runtest'

Conflicts:
	test/RunTests