default loglevel "http" → "warn"
Ensure that npm-debug.log file is created when rollbacks are done
lock cache → lock target

Rip out locking logic obviated by the new emphasis on atomic writes
within the cache; ensure that only one process can be writing to a given
module in node_modules at a time. All the tests pass?
code style tweaks
update changelog for npm@2.1.0
2.1.0
remove locking code around packing and unpacking
clean up locking; prefix lockfile with "."
2.1.1
update changelog for npm@2.1.1
Explain how to pass arguments to scripts