context: use portable construction to verify int parsing

ui: portably bytestring-ify url object

scmutil: fix key generation to portably bytestringify integer

branchmap: stringify int in a portable way We actually need a bytes in Python 3, and thanks to our nasty source loader this will portably do the right thing.

branchmap: don't use buffer() on Python 3 This is certainly slower than the Python 2 code, but it works, and we can revisit it later if it's a problem.

py3: use bytearray() instead of array('c', ...) constructions Portable from 2.6-3.6.

summary: don't explicitly str() something we're about to %s str() is wrong on Python 3 here, and %s implicitly calls str() anyway, so this was just extra dancing for no reason.

context: implement both __bytes__ and __str__ for Python 3 They're very similar, for obvious reasons.

context: work around `long` not existing on Python 3 I can't figure out what this branch is even trying to accomplish, and it was introduced in ac89a23ca814 which doesn't really shed any insight into why longs are treated differently from ints.

phases: explicitly evaluate list returned by map On Python 3 map() returns a generator, which bool()s to true even if it had an empty input set. Work around this by using list() on the map() result.