fixes pathological case where imports with randomly ordered IDs which
spanned multiple shards and included ints or mutex fields could be
incredibly slow due to making 1000s of requests.
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
```
Time fields were not listed as a type which could accept key translation, causing the translation code to fail.
This also adds tests for keyed time and mutex fields.
This migrates existing code from the old TranslateKey(s) endpoints to the newer CreateKeys and FindKeys endpoints.
The CreateKeys and FindKeys endpoints were created previously as the TranslateKeys endpoint had no way to behave sanely when the looked-up key did not exist (the parallel-arrays representation did not have a good way to represent a missing key).
This change also removes the old TranslateKey(s) functions from the translation stores.
It leaves a wrapper emulating the TranslateKey(s) endpoints so that old idk still works for now.
