Support for a "SpanAndQuery" / "SpanAllNearQuery" [LUCENE-3371]

I would like to parse queries like this:

```
a WITHIN 5 WORDS OF (b AND c)
```

This would match cases where both a b span and a c span are within 5 of the same a span.

The existing span query classes do not appear to be capable of doing this no matter how they are combined, although replacing the AND with "WITHIN 10 OF" (general rule is to double the first number) at least ensures that no hits are lost (it just returns too many.)

I'm not sure how the class would work, but it might be like this:

```Java
Query q = new SpanAllNearQuery(a, new SpanQuery[] { b, c }, 5, false);
```

The difference from SpanNearQuery is that SpanNearQuery considers the entire collection of terms as a single set to be found near each other, whereas this query would consider each of the terms in the array relative to the first.

---
Migrated from [LUCENE-3371](https://issues.apache.org/jira/browse/LUCENE-3371) by Trejkaz, updated Sep 07 2016

Start by reading SpanNearQuery and the existing span query classes to determine how span relationships are represented. Define how SpanAllNearQuery should evaluate each term relative to the first span, then verify that the example query matches the described cases without the false positives introduced by doubling the distance.

Written by the indexing model from the issue text.