added include_lower and include_upper properties to RangeFilter

Hi Shay,

based on the conversation we had on the mailing list, I field the following issue:
https://github.com/elasticsearch/elasticsearch/issues/1092) 
and provided a patch for it. 

The difficult part was to get eclipse configured correctly with gradle. I basically ended up using the eclipse plugin from gradle that generated config files and it worked like a charm! 

When I get a change I will add a section to the doc for those who want to use Eclipse with ES source code