Only load packages as they are passed to resolve

(and their transitive dependencies)
Don't load mori module until needed

Slightly speeds up commands that don't resolve constraints
check config file for version before using it
Use catalog.complete instead of catalog.official

Specifically, in cases (like "load the most recent release we know
about") where we don't always want to incur a sync RPC.

Apparently, there is literally no way to get data from catalog.official
without a sync RPC occuring.

This speeds up 'meteor --version' on built releases by a factor of 10