better gofmt formatting:
- first cut a better line breaks in expr lists
- trailing commas and semis printed where we tend to write them
- fixed a couple of minor spacing issues (interface{}, chan<-, map[x]y, x: y)
- removed some formatting flags from gofmt: no need to change default
- removed option to reverse declaration order when printing
- excluded files from test that cause trouble with idempotency test for now