gofmt: modified algorithm for alignment of multi-line composite/list entries
- only manual changes are in src/pkg/go/printer/nodes.go
- use a heuristic to determine "outliers" such that not entire composites are
forced to align with them
- improves several places that were not unligned before due too simple heuristic
- unalignes some cases that contain "outliers"
- gofmt -w src misc
Fixes #644.
R=rsc, r
CC=golang-dev
https://golang.org/cl/241041