py3: replace sys.platform with pycompat.sysplatform (part 1 of 2) sys.platform returns unicode on python 3 world. Our code base has most of the things bytes because of the transformer. So we have a bytes version of this as pycompat.sysplatform. This series of 2 patches replaces occurences of sys.platform with pycompat.sysplatform.

py3: replace os.name with pycompat.osname (part 2 of 2)

py3: replace os.name with pycompat.osname (part 1 of 2) os.name returns unicodes on py3 and we have pycompat.osname which returns bytes. This series of 2 patches will change every ocurrence of os.name with pycompat.osname.