confirm that empty IDs are really wanted
always ask
Adjust import order
Adjust copyright headers
Trivial spacing changes to conform to style guide
Adjust variable/member naming to conform to style guide

In some cases change member accessibility, so the naming matches.
Also, some key words were reordered to comply with JLS suggestions.
Rearrange too long lines
Add missing and curly brackets and fix others

Style guide demands them even for single-line blocks, and opening
curly brackets never appear on a line on their own.
Suppress checkstyle for some files