ui: convert to/from Unicode on Python 3 in ui.editor()...
ui: convert to/from Unicode on Python 3 in ui.editor()
I considered making this I/O be done in terms of bytes, but that would
cause an observable regression for Windows users, as non-binary-mode
open does EOL conversion there. There are probably new encoding
dragons lurking here, so we may want to switch to using binary mode
and doing EOL conversion ourselves.
