Normalize and standardise manifests about pacote

[iarna]

Yes, do run the manifest through normalize-package-data, in particular, because it normalizes things like bundleDependencies/bundledDependencies.

Ok, so to the best of my knowledge the required keys are:

name
version
dependencies
optionalDependencies
devDependencies
bundleDependencies
peerDependencies
bin

Also these, which are from various places in the cache currently:

• _resolved, _from - these are where resolved and from in the shrinkwrap come from. They're also used throughout the installer.
• _id, _shasum - are added by the existing cache code.
• _spec - This is a fetch-package-metadata artifact and should be removed.

[iarna]

normalize-package-data also copies all of the optionalDependencies into dependencies.

[zkat]

We're currently adding _shrinkwrap as well (pacote-side, sometimes maybe registry-side?)

Also, the bin thing is also mentioned over at #18

[zkat]

Note: _id is not needed, but will probably get shoved in there anyway by normalize-package-data.