Clean up/strengthen the noinit tests.

Previously, the noinit tests had relied on accurate
later assignment and a hacky grep of the generated
code (in the case of enums as it was simpliest) to
assure us that default initialization had been properly
skipped.  Brad had suggested way back when that we
would be able to better test if noinit had actually worked
by using the _defaultOf functionality - by redefining the
default behavior to include displaying a message
whenever it was invoked, the absence of this
message would indicate when the default behavior
did not occur.  Now that _defaultOf is in the language,
I have replaced/updated some of the tests in this
directory to use this improved method of determination.

I also removed the .future files and updated the .goods
for syncs and singles, as the team has felt for a while
that their current behavior was correct.
The default and noinit behavior for sync variables is worthy of a group discussion, so I would have left it as a future.
It may be that we can't support noinit for sync variables right now, but setting down expectations for future behavior is exactly what futures are for.