setup: convert setupversion to unicode Something deep in the bowels of distutils expects "version" passed to setup() to be a str/unicode. So, convert the type. This still works on Python 2 because the string is ascii and an implicit coercion back to str/bytes should work without issue. If it does cause problems, we can always make the unicode conversion dependent on running Python 3. This change makes `python3.5 setup.py install` work.

util: add debugstacktrace depth limit Useful when you don't care about the start of the stack, but only want to see the last entries.

util: strip trailing newline from debugstacktrace message This makes the function more convenient to use as drop-in replacement for ui.write & co.

tests: rework util.debugstacktrace tests Prepare for adding another test.

vfs: use repo.vfs.rename

vfs: use repo.vfs.unlinkpath

merge: use repo.wvfs.unlinkpath

vfs: use repo.wvfs.unlinkpath

policy: try and always have a bytes for module policy debuginstall now runs cleanly in Python 3.

init: zstd is already python3-ready, so don't run it through our importer