help: don't display bogus help messages for invalid aliases

run-tests: install data files correctly In 68964567e406 we began installing some data files in PREFIX/share. When preparing to run the tests, run-tests.py uses --home="" in order to work around home being set in a ~/.pydistutils.cfg file. This somehow overwrites the --prefix option. The result was that the share/ directory was installed in the top of the Mercurial source tree.

Merge with stable

patchbomb: handle repository#rev URLs correctly

contrib: helper extension to track memory usage

export: fix tests

commands.export: accept -r option as revision specification This brings consistency with other commands option and allows specification of negative numbers (-r -2), which were recognized as options earlier.