templater: always join() over a wrapped object (BC)...
templater: always join() over a wrapped object (BC)
This is a behavior change in a sense that join() of a byte string is no
longer "implementation dependent." Before, if a byte string was backed by
a lazy generator, join() would concatenate each chunk with the specified
separator, which seems wrong. The new behavior is always join() each byte.
TypeError on join() over uniterable is also fixed.