This patch is squashed from a few commits.
sancov.py: [Py3] Get rid of "print" statement. Use print() or write() instead.
sancov.py: [Py3] Use '//' instead of '/' as division operator. Py3 emits float with '/'.
Py3 has '//' as integer division operator.
sancov.py: [Py3] Use sys.stdout.buffer for bytes.
Py2 doesn't have sys.stdout.buffer. An idea from http://stackoverflow.com/questions/23932332
sancov.py: [Py3] Use bytes.decode() explicitly. Or bogus filename like "b'foo'" would be generated.