Zodbdump format is text-binary and is saved into files opened in binary
mode. -> We have to emit bytes - not strings - into it, since otherwise
on Python3 it would break.

This needs qq support from pygolang[1] to be able to use qq with both
string and bytestring format, e.g. for

	 "hello %s" % qq(name),	and
	b"hello %s" % qq(name)

to give the same output irregardless of whether name is str or bytes.

[1] nexedi/pygolang!1