SF #596434: tweak wordsep_re so the definition of an em-dash is stricter: specifically, "--" must be preceded by a limited set of characters, not by any non-whitespace character.
SF #596434: tweak wordsep_re so the definition of an em-dash is
stricter: specifically, "--" must be preceded by a limited set of
characters, not by any non-whitespace character.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator