Work on radius geo filter
Implements #477
Conflicts:
	src/main/java/com/jaeksoft/searchlib/cache/FilterCache.java
	src/main/java/com/jaeksoft/searchlib/filter/AuthFilter.java
	src/main/java/com/jaeksoft/searchlib/filter/FilterAbstract.java
	src/main/java/com/jaeksoft/searchlib/filter/GeoFilter.java
	src/main/java/com/jaeksoft/searchlib/filter/QueryFilter.java
	src/main/java/com/jaeksoft/searchlib/filter/RelativeDateFilter.java
	src/main/java/com/jaeksoft/searchlib/filter/TermFilter.java
	src/main/java/com/jaeksoft/searchlib/index/DocSetHitCacheKey.java
	src/main/java/com/jaeksoft/searchlib/index/IndexSingle.java