Revision 494136

LUCENE-140: Add bounds checking to BitVector's get, set, clear methods
to prevent index corruption on calling IndexReader.deleteDocument(int
docNum) on a "slightly" out of bounds docNum.  Other changes:

  * In IndexReader.deleteDocument, set hasChanges to true before
    calling doDelete in case an Exception is hit in doDelete.

  * Changed the "docs out of order" check to be tighter (<= instead of
    <) to catch boundary case that was missed.

  * Fixed small unrelated javadoc typo.