tests: port test-extensions-wrapfunction to Python 3 Differential Revision: https://phab.mercurial-scm.org/D3527

tests: port test-ui-config to Python 3 Slight test output changes to make life easier. Differential Revision: https://phab.mercurial-scm.org/D3526

config: fix py3 backslash escaping bug in parser caught by tests Differential Revision: https://phab.mercurial-scm.org/D3525

tests: port test-symlink-os-yes-fs-no.py to Python 3 # skip-blame just bytes/str changes Differential Revision: https://phab.mercurial-scm.org/D3524

posix: use inst.errno instead of inst[0] on OSError instances Differential Revision: https://phab.mercurial-scm.org/D3523

tests: port test-filelog.py to Python 3 # skip-blame just some bytes prefixes Differential Revision: https://phab.mercurial-scm.org/D3522

stringutil: teach pprint about tuples Differential Revision: https://phab.mercurial-scm.org/D3521

templatefuncs: show hint if extdata source is evaluated to empty (issue5843)

revlog: use literal -1 instead of variable that always has that value We were setting "ntrev" to "rev", but "rev" was always -1 at the end of the loop, so it's clearer to use a literal -1. Differential Revision: https://phab.mercurial-scm.org/D3498

revlog: extract function for fully populating the radix tree This code is currently used for partialmatch(), but I want to reuse it when I implement shortest() in native code. Differential Revision: https://phab.mercurial-scm.org/D3497