lazyindex: speed up __getitem__ This function is fairly performance sensitive, so we make a couple ugly tweaks: - keep all entries packed so we needn't test entry types - fold index lookup/load into unpack call to eliminate local variable setting

To run the tests, do:

cd tests/
python run-tests.py

See http://www.selenic.com/mercurial/wiki/index.cgi/WritingTests for
more information on writing tests.