ValuesSourceConfig is now evaluated in the ValuesSourceAggregatorFactory instead of ValueSourceParser. This means that the ValueSourceParser purely deals with parsing the XContent and the logic requiring access to the mappings etc. on the shard is left to the ValuesSourceAggregatorFactory. This means that, in the future, the parsing logic can be moved to the coordinating node.

This change adds AbstractValuesSourceParser which will be the new class used to create ValuesSourceAggregatorFactory objects. AbstractValuesSourceParser parses all the parameters required for ValuesSource and passes to the sub-class to parse any other (implementation specific) parameters. After parsing is complete it will call createFactory on the implementing class to create the AggregatorFactory object and then set the ValuesSource specific parameters before returning it.

ValuesSourceAggregatorFactory also now has setter methods so that it can be used as the 'builder' object in the future.

Also makes AggregatorFactories implement Writable

…egation

…um Bucket, Percentiles Bucket, Stats Bucket and Extended Stats Bucket Aggregations

# Conflicts:
#	core/src/main/java/org/elasticsearch/search/aggregations/bucket/children/ChildrenParser.java
#	core/src/main/java/org/elasticsearch/search/aggregations/support/ValuesSourceParser.java
#	test/framework/src/main/java/org/elasticsearch/test/TestSearchContext.java

# Conflicts:
#	core/src/main/java/org/elasticsearch/percolator/PercolatorService.java
#	core/src/main/java/org/elasticsearch/percolator/QueryCollector.java

…ods chain able

….Factory and ExtendedStatsAggregator.Factory

…ions

# Conflicts:
#	core/src/main/java/org/elasticsearch/common/io/stream/StreamInput.java
#	core/src/main/java/org/elasticsearch/common/io/stream/StreamOutput.java

# Conflicts:
#	core/src/main/java/org/elasticsearch/search/aggregations/bucket/filter/FilterAggregator.java
#	core/src/main/java/org/elasticsearch/search/aggregations/bucket/filters/FiltersAggregator.java
#	core/src/main/java/org/elasticsearch/search/SearchModule.java

# Conflicts:
#	core/src/test/java/org/elasticsearch/percolator/PercolateDocumentParserTests.java

…tions

# Conflicts:
#	core/src/main/java/org/elasticsearch/common/io/stream/StreamInput.java
#	core/src/main/java/org/elasticsearch/common/io/stream/StreamOutput.java
#	core/src/main/java/org/elasticsearch/search/SearchModule.java

# Conflicts:
#	core/src/main/java/org/elasticsearch/action/search/SearchRequestBuilder.java
#	core/src/main/java/org/elasticsearch/percolator/PercolateContext.java
#	core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/ScriptHeuristic.java
#	core/src/main/java/org/elasticsearch/search/internal/DefaultSearchContext.java
#	core/src/test/java/org/elasticsearch/search/aggregations/bucket/significant/SignificanceHeuristicTests.java

# Conflicts:
#	core/src/test/java/org/elasticsearch/search/aggregations/AggregationsBinaryIT.java
#	core/src/test/java/org/elasticsearch/search/aggregations/bucket/FilterIT.java
#	core/src/test/java/org/elasticsearch/search/aggregations/bucket/FiltersIT.java
#	core/src/test/java/org/elasticsearch/search/aggregations/bucket/GeoDistanceIT.java
#	core/src/test/java/org/elasticsearch/search/aggregations/bucket/NestedIT.java
#	core/src/test/java/org/elasticsearch/search/aggregations/bucket/SamplerIT.java
#	core/src/test/java/org/elasticsearch/search/aggregations/pipeline/DerivativeIT.java
#	modules/lang-groovy/src/test/java/org/elasticsearch/messy/tests/BucketSelectorTests.java
#	modules/lang-groovy/src/test/java/org/elasticsearch/messy/tests/TDigestPercentileRanksTests.java

# Conflicts:
#	core/src/main/java/org/elasticsearch/common/io/stream/StreamInput.java
#	core/src/main/java/org/elasticsearch/common/io/stream/StreamOutput.java

…ctories and metadata in the constructor

# Conflicts:
#	core/src/main/java/org/elasticsearch/percolator/PercolateContext.java
#	core/src/main/java/org/elasticsearch/search/aggregations/bucket/filter/FilterParser.java
#	core/src/main/java/org/elasticsearch/search/aggregations/bucket/filters/FiltersParser.java
#	core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsParametersParser.java
#	core/src/main/java/org/elasticsearch/search/internal/DefaultSearchContext.java
#	core/src/test/java/org/elasticsearch/search/aggregations/bucket/geogrid/GeoHashGridParserTests.java
#	test/framework/src/main/java/org/elasticsearch/test/TestSearchContext.java

…om createInternal() parameters

Also renames all the implementations appropriately

# Conflicts:
#	core/src/main/java/org/elasticsearch/search/SearchService.java
#	test/framework/src/main/java/org/elasticsearch/search/MockSearchService.java

# Conflicts:
#	core/src/test/java/org/elasticsearch/search/builder/SearchSourceBuilderTests.java