fix typo, thanks @dgreensp
generate-dev-bundle: use local node/mongo tarballs

(kind of like the dev bundle itself)
separate server deps from tool deps

move package.json to a JS file so it can have comments.
move tool deps to package.json to run npm dedupe
switch unmatched pushd to cd
Merge branch 'dev-bundle-cleanups' into devel
Install pathwatcher from NPM instead of GitHub.
Make a note of future aspirations about installing pathwatcher.
Trigger a rebuild to pick up @glasser's dev_bundle/server-lib changes.
Implement funcUtils.coalesce(delayMs, callback).
Use pathwatcher.watch to trigger rebuilds and restart the server.

Fixes #2135.