Description
rcmuir noticed that Lucene60PointReader does not detect truncation of its data file on reader init ... so I added a test to catch this, confirmed it caught the bug, and fixed the bug, and fixed a couple other things uncovered by the test.
I also improved the other TestAllFiles* tests to use LineFileDocs so they index points, and it caught another bug in Lucene60PointFormat (using the same codec name in two files).
There is more to do here, e.g. we also need a test that catches places where we fail to check the index header on init, which was also missing for Lucene60PointReader.