Page pred test2

While making a stabilizer test from,  Queries and Indexing,  I found some infinite loop problems using paging predicate.  

I am adding some junit tests to clarify paging predicate behavior, when the underlying data is being change while the paging predicate is used.


PagingPredicate holds the state of last query (the last entry of the query as anchor to query the next page).
For example if we list values with an order (pageSize=5):
1,2,3,4,5 -> '5' is the anchor here
6,7,8,9,10 -> '10' is the anchor here
for the 3rd query we use '10' to filter out first two pages. so we fetch 5 values which are greater than the anchor '10'
If you insert the value before 10 then the 3rd query will not contain it.

for un-ordered queries, we use a natural order (hash of entry)
since we cannot predict hash of entries result is not predictable too