[PATCH] BooleanScorer2 ArrayIndexOutOfBoundsException + alternative NearSpans

From Erik's post at java-dev:

>      [java] Caused by: java.lang.ArrayIndexOutOfBoundsException: 4
>      [java]     at org.apache.lucene.search.BooleanScorer2
> $Coordinator.coordFactor(BooleanScorer2.java:54)
>      [java]     at org.apache.lucene.search.BooleanScorer2.score
> (BooleanScorer2.java:292)
...

and my answer:

Probably nrMatchers is increased too often in score() by calling score()
more than once.