[GEOS-6654] Refer to right Xlink XSD in WFS

In WFS 2.0 the wrong Xlink XSD was linked, instead of using the original
W3 Xlink, the old and deprecated OGC Xlink was used.  This change should
not impact further functionality of the WFS module.
Enable geojson geometry output in WPS
Fixed jms-cluster artifactId and removed inconsistent property activation
Merge branch 'wps-geojson-for-geometries'

Conflicts:
	src/extension/wps/wps-core/src/test/java/org/geoserver/wps/jts/GeometryProcessWPSTest.java
Merge pull request #764 from Geodan/GEOS-6654

[GEOS-6654] Refer to right Xlink XSD in WFS
Allow StyleGenerator to create style inside of a workspace.
Merge pull request #776 from jdeolive/style-gen-workspace

Allow StyleGenerator to create style inside of a workspace.
Added DataStoreFactoryInitializer for GeoPkg. Fixes GEOS-6708.
[GEOS-6707] SortBy property name validation breaks app-schema
Fixed jms-cluster artifactId in community release pom
Fixing some issues reported by Mark Jansen during a pull request review
GEOS-6711: improvements for the authkey module, by mapper parameters and
new webservice mapper
GEOS-6711: added some documentation for the improvements
GEOS-6716, Add SolR plugin to the community release
Merge pull request #780 from geosolutions-it/solr-release

GEOS-6716, Add SolR plugin to the community release
Merge pull request #778 from mbarto/geos_6711_authkey_webservice

GEOS-6711: improvements for the authkey module, by mapper parameters and new webservice mapper
Adding SOLR data store docs
[GEOS-6717] Improve store param hover labels
[GEOS-6718] Allow the admin to specify which SOLR geometry attribute should be the default one
Document choosing default geometry field