Added Script test for geo distance tests and modified GeoUtils.normalizePoint()
Fix issue where entire shards are lost due to too many open files exceptions and a but in Lucene's
IndexWriter / DirectoryReader where an existsing index was not detected and then deleted due to a wrong
creation mode. See LUCENE-4870

Closes #2812
Fixes java6_u31 compile error w.r.t. type inference
Adding parsing for zero terms query for multi match
Tests for multi-match zero_terms_query and making references to the ZeroTermsQuery enum consistent to others used in MultiMatchQueryBuilder
add 0.20.7