Nested filter supports now the setFilter method.

When using elastica to perform a search using only filters there was no method
to set an AbstractFilter to the nested Filter so I've added the setFilter method.
Create test for the NestedFilter that supports setFilter.
Also pass Client to callback

Makes it possible to inspect other possible connections
Update changes.txt and add rudimentary test for callback additions
Merge changes.txt conflicts
Merge changes.txt conflicts
Update to elasticsearch 0.90.5
Release v0.90.5.0
Update README to newest release
dev-master alias removed as not used anymore
Fix json error (closing ,) in composer.json
Adapted possible values (not only in) for minimum_should_match param based on elasticsearch documetnation  http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/query-dsl-minimum-should-match.html
Merge remote branch 'upstream/master'

Conflicts:
	changes.txt