Fixes for quantified comparison predicates and other changes

#1057, #1072 fix subquery result cache in lazy mode

This reverts commit 138b31ca.

for subquery in joins/nested joins recursively

Return BIGINT from ROWNUM(), ROW_NUMBER() and rank functions

cleanup StringUtils.cache

Minor changes in parser and documentation

1. No need to call `hashCode` if  `cache=null`
2. Remove redundant `null` comparison. `String.equals` will anyway return `false`