Merge pull request #290 from CGenie/cgenie

TermsQuery fixes for minimum_match and boost
Terms facet can have a script, without field or fields.  Regex requires either field or fields
Merge pull request #291 from chrisguiney/bugfix/terms-facet-script

Terms facet can have a script, without field or fields.  Regex requires ...
Implement additional options for RabbitMQRiver
Merge pull request #292 from jlinn/master

Implement additional RabbitMQRiver options
Feature: added missing CustomBoostFactoryQuery

http://www.elasticsearch.org/guide/reference/query-dsl/custom-boost-fact
or-query/ added as pyes class
Merge pull request #294 from julianhille/master

Added a new feature for the custom_boost_factor query. Added tests also.
Bugfix: "ValueError: too many values to unpack"
Merge pull request #295 from mindflayer/patch-1

Bugfix: "ValueError: too many values to unpack"
Add 'existence' and 'null_value' options for MissingFilter