Fix performance of hg diff.
commands.walk has been refactored. commands.walk's behaviour remains as
it was, but there is a new function, commands.makewalk. This returns
results that can be passed along to other internal code, in our case
dodiff.
include hg
recursive-include mercurial *.py
include hgweb.cgi
include hgeditor rewrite-log
include tests/README tests/run-tests tests/test-*[a-z0-9] tests/*.out
prune tests/*.err
include *.txt
include templates/map templates/map-*[a-z0-9]
include templates/*.tmpl
include doc/README doc/*.txt doc/Makefile
recursive-include contrib *
include README
include CONTRIBUTORS
include COPYING
include TODO
include MANIFEST.in