statichttprepo: unbyteify several IOError messages Builtin errors generally want str messages.

statichttprepo: fix the vfs.join() method to match the base class definition Flagged by PyCharm. The superclass implementation raised NotImplementedError.

mail: unbyteify the SMTPException message This is a subclass of OSError, which wants str instead of bytes.

mail: add a missing argument to properly override starttls I didn't look into when this changed, but it was flagged by PyCharm.

crecord: switch a curses argument to bool to appease type checkers

grep: avoid reassigning byteskwargs to strkwargs PyCharm flagged each of these `get()` calls with bytes. We still pass the bytes form to the formatter to avoid changing the API, until all callers can be changed.

cat: drop unnecessary internal roundtrip of kwargs PyCharm seems to stick with the type at the initial assignment, so it flagged the `get()` with a bytes key since the method argument has str keys. It wasn't a bug, but then the bytes form is otherwise unused, and converted back to str.

relnotes: add 6.4 and empty next

Added signature for changeset 05de4896508e

Added tag 6.4rc0 for changeset 05de4896508e