Figure out "Organize imports" config

[arthurp]

The current Scala Organize Imports config is very ad-hoc. It has a number of current issues:

• By default it removes all wildcard imports and replaces them with enumerated lists. This is really noisy and in some cases much more confusing. We can configure certain packages to always use wildcards (Arthur did this, but isn't too happy with his choices). We could also configure the system to leave manually added wildcards.
• We should figure out how to make running Scala Organize imports run automatically on all Scala files.