revsetlang: add a hint for more useful parse errors This logic is largely based on the similar logic added to template error messages in D2608 and D2609, but with a few tweaks based on how revsets actually work. Differential Revision: https://phab.mercurial-scm.org/D2619

setup: ignore extension load failures when finding working hg Previously, `make local` would fail if any extension was not properly loading. Differential Revision: https://phab.mercurial-scm.org/D2589

profile: colorize output on Windows Previously, the ANSI codes were printed to the screen, throwing off the alignment. We could probably do this unconditionally, but it's kind of a hack, so I figured I'd limit the scope.

dispatch: don't clamp the range of the exit code twice We already limit the range to (0, 255) in the call to sys.exit(). The duplicated operation can't possibly be hurting us, but let's clean it up to avoid confusion.