ACCUMULO-1988 Fix calls to several example functional tests

- The Accumulo 1.5.x package no longer includes source, so the example test that
  builds a sharded index found no Java files. This commit changes the indexing to
  use the source code for examples, which is still included.
- The million-row TeraSortIngest example erroneously passed the -nk and -xk options
  twice. This commit changes the second set of options to -nv and -xv, which is
  what they should have been.
- The following example test intends to output to the tmp/nines file, but the
  required "--output" was missing in the command line. It was added.
- The example after that used to write row hashes to a separate table, but today the
  job writes to the same table. A vestigial command line argument for that table
  prevented the job from running, so it was removed.
- In between the last three tests, and between the last text and the next one, the
  examples.py script was removing and recreating the test table, which meant that
  all but the first test were running against zero rows. The table is now left
  intact between the four tests.