repeat testDataByLocaleOrdering with different save methods

- Factor out the save method into interface SaveMethod.
- Introduce testDataByLocaleOrderingFlushTus (identical to the old
  testDataByLocaleOrdering) and testDataByLocaleOrderingSaveMultiple.
- Add a code commenton clarifying why testDataByLocaleOrderingSaveMultiple
  works.
handy fuzz matching test data
use fuzzy test data in testFuzzyLookupKeyLocaleAndLookupTarget
testBadLocale for BilingualTm

Obviously this test should fail early, but amazingly it all passes!  I added
an exception and structured it as an "expected fail" (which JUnit doesn't
realy have) to try to make this clear.
doc tweak
Merge pull request #8 from pimlott/master

More tests, a little doc.