manifest: add __nonzero__ method This adds a __nonzero__ method to manifestdict. This isn't strictly necessary in the vanilla Mercurial implementation, since Python will handle nonzero checks by using __len__, but having it implemented here makes it easier for alternative implementations to implement __nonzero__ and have them be plug-n-play with the normal implementation.

py3: have bytes version of sys.argv sys.argv returns unicodes on Python 3. We need a bytes version for us. There was also a python bug/feature request which wanted then to implement one. They rejected and it is quoted in one of the comments that we can use fsencode() to get a bytes version of sys.argv. Though not sure about its correctness. Link to the comment: http://bugs.python.org/issue8776#msg217416 After this patch we will have pycompat.sysargv which will return us bytes version of sys.argv. If this patch goes in, i will like to make transformer rewrite sys.argv with pycompat.argv because there are lot of occurences.

util: use '\\' rather than using r'\' We need bytes, and I find this just a little more immediately obvious than doing rb'\'.