revert: move code dealing with deletions closer together

ui: fix configlist on Python 3 Since we're working on bytestrings, we have to use [offset:offset+1] to get consistent behavior on Python 2 and 3. I've only tested the _parse_plain closure, not the _parse_quote one, but I have no real reason to expect the latter to be broken since the fixes were fairly mechanical.

config: pass some optional args as keywords This makes it a little more obvious that self.read is being passed as include, which took me a moment to figure out.

config: load included config files in binary mode I guess we've been getting lucky that this works in Python 2. This fixes loading included config files in Python 3 (it used to fail on the "somebody set up us the BOM" check.)