re #880 - Ensures that a nested filter consisting of only a filter does not result in a conditionless NEST filter (leading to its exclusion from generated json query)
Add method to check if empty collections should be included in result serialized json result
Update documentation
Update descriptor's with Fields()/Path()
Update mappings to allow inheritance for multifieldmap
Add multifieldmap also the GenericMapping
Change mapping to use contructor for default type
Fix full mapping test

If store and enable are the same values as the server are configured as
the items are not returned back as response when get-mapping are
executed.
Test has wrong base class
Test-issie is still not solved in ES
Skip term vector id tests on ES versions >= 1.2
Add static method or Wildcard query based on descriptor
BinaryMapping also inherit from MultiFieldMapping