Review API for Query result iterators

I have found multiple problems with the iterators returned by CacheQueryImpl.

• using LazyIterator with fetchSize fails with ArrayIndexOutOfBoundsException
• calling previous() after next() doesn't return expected element
• calling nextIndex() on a new iterator should return 0, not 1 (the same also applies when calling nextIndex() after calling first())
• if fetchSize is greater than 1, LazyIterator fills the whole buffer on every invocation of .previous() (if fetchSize = 10, then every invocation of previous() loads 10 results from the cache)
• nextIndex() and previousIndex() throw NoSuchElementException, which violates the contract of ListInterface
• next() and previous() throw ArrayIndexOutOfBoundsException when they should be throwing NoSuchElementException
• ...