Cobra automatically displays usage messages, and also a gratuitous
"Error: [...]" line in some cases, when any error at all occurs
running a command. To suppress the usage message, you have to set
cmd.SilenceUsage to true. But the code that would do this doesn't
have access to it. To address this, we introduce a category of
"usage error", implemented with stdlib error wrapping (%w) and
use errors.Is to check for it. There's also utility functions
to do this checking automatically, or indeed, to handle wrapping
of the ctl.SomethingCommand and handle running it with a suitable
context and everything.
In fact, several of the places we're checking for usage errors,
we can never actually report one, but we're checking consistently
so that if we want to report usage errors, we can.
For instance, server.Start and (dax)server.Start don't ever
return usage errors, right now, but we're checking their responses
anyway.
This adds a shard-based import endpoint which takes bitmap data for
all field types and imports data for the whole shard transactionally.
It uses the BitmapRewriter interface to try to intelligently allow for
setting and clearing bits simultaneously without multiple writes which
is especially helpful when ingesting into int-like fields, but also
allows clear-and-then-set behavior for set fields.
i used this script, a little clunky but it got the job done
```bash
for file in `find . -type f -print | grep '\.go'`; do
sed '1,/^\/\/ limitations under the License.$/d' $file > $file.tmp;
result=`cat $file.tmp`
if [[ result != "" ]]; then
gofmt $file.tmp &> /dev/null;
if [[ $? == 0 ]]; then
mv $file.tmp $file && gofmt -w $file;
else
rm $file.tmp;
fi
else
rm $file.tmp;
fi
done
```
