v4.0.0

• d67b8da - convert Date element to an int when saving to elastcisearch bcause it is a timestamp. null will become 0
• e7176bc - Added filter cluse to BoolQuery object to support elasticsearch 5 dsl
• d6018b3 - Fixed bug to allow filter and must to both be supplied to a query bool
• fe67c4f - Added an input element processor. Also changed the select element processor to not try and fetch objects from the database if the value is numeric because most of the time it will just be an auto increment value and will end up with incorrect data associated to it. Also now uses the input element processor as the fallback for select