revlog: if start is nullrev, end is always a descendant

mq: use sets instead of lists for speed The code eventually converts data through sets to ensure unicity: do it earlier to allow faster __contains__ lookups and avoid `del l[l.index(x)]` kind of code.

context: add __repr__ methods to workingfilectx and workingctx

merge with crew

test-import: workaround for missing newline is no longer needed

merge with stable

tests: use (esc) instead of other kinds of string escaping

tests: use (esc) for all non-ASCII test output

tests: use (esc) markup for string-escape This makes test output less ambiguous. Failing test output will be escaped and marked up if necessary. A Python string-escape compatible encoding is used, but not everything is encoded - especially not \n and \t and '.

tests: (no-eol) markup for command output without trailing LF Output chunks without a trailing LF will now work but get (no-eol) appended. This change mostly moves code around so we can handle that an output line starts with data from previous command, followed by salt and the next command.