v2 patch. Three changes to the first patch:
1. Fixes a bug I introduced in o.a.h.mapred.LineRecordReader where the key would not be properly set if a line is too long and is skipped.
2. o.a.h.mapred.LineRecordReader#getProgress should use getFilePosition, and therefore callers need to handle or declare they may throw IOE. This change was not in the patch for 772 or 830 but is present in 0.23.
3. o.a.h.mapreduce.LineRecordReader#getProgress should use getFilePosition, also now throws IOE.
All tests pass locally except for the previously reported unrelated failure.