Misc refactoring and test fixes

Misc refactoring and test fixes

This changeset turns on automatic formatting of the affected regions
in extract include, change layout, wrap in and style refactorings.

It also fixes a couple of minor bugs - one handling empty tags in the
change widget type refactoring, and one handling selection offsets.

It also turns on automatic formatting of GUI editor changes (there was
a previous changeset which prepared for this but forgot to actually
switch the default option.)

This changeset also makes various test infrastructure fixes: code
completion tests recently stopped working for a number of files
(something about the initialization order of editor types when running
as tests).  I also tweaked the goldenfile format of the diffs to avoid
trailing diffs on lines with just a ">" or "<" since gerrit makes thee
light up in red.

Change-Id: I78b858f0b21e5b2f25a9566ad495bad09c66a18f