path::normalize description

[jesse99]

Currently this says "Removes extra '.' and '..' entries from paths". This is kind of confusing: it's not exactly clear what extra means in this context. It would be clearer to use something like: "Removes '.' and '..' entries from paths".

[brson]

I updated the docs to try to make it more clear what the function does, though it's still not exceptionally lucid. Please submit a patch if you have something better.