Remove package scripts before install

[aleclarson]

Any package.json scripts that would run on npm install will be removed while dependencies are being installed. This lets us install parent packages first without the fear of a child package not being ready-to-use in a script.

Why would I want that? Installing dependencies of parents first lets children use link: to inherit dev dependencies from their parents. This reduces install times.

The removed scripts are restored after install, and they're executed in topological order (children first).