test-alias: add some tests to ensure we aren't double-substituting
An earlier iteration of an upcoming patch caused inadvertent
double substitution. Ensure we have test coverage for this.
to build a new macosx binary package:
install macpython from http://www.python.org/download/mac
install py2app from http://pythonmac.org/packages/
make sure /usr/local/bin is in your path
run bdist_mpkg in top-level hg directory
find packaged stuff in dist directory