[GEOS-5993] Missing ElectronicMailAddress in WFS capabilities

In the WFS capabilities there were missing two important fields that are
present in the XSD. Those fields are ElectronicMailAddress and
DeliveryPoint.

This commit adds those two fields, but disregards the fact that there
can be more than one of both fields. However this patch could be adapted
to create a List or Array of both, so they are more faithful to the XSD.
[GEOS-5993] Added a test in the WFS Capabilities Transformer test for Contact information added to WFS.
[GEOS-5993] Added GUI support for DeliveryPoint and ElectronicMailAddress.
Implemented hashCode and equals methods.
Updated SLD cookbook 3-color gradient to match current behavior
[GEOS-6785]WCS GetCapabilities 1.1.1 has invalid metadataType attribute

WCS GetCapabilities request had a metadataType attribute which isn't allowed according to the XSD (owsCommon 1.1.1). Thus I have removed this item from being generated.
Merge pull request #833 from Geodan/GEOS-6785

[GEOS-6785]WCS GetCapabilities 1.1.1 has invalid metadataType attribute
Merge pull request #815 from tbarsballe/sldcookbook

Updated SLD cookbook 3-color gradient to match current behavior
Merge pull request #762 from Geodan/GEOS-5993

[GEOS-5993] Missing ElectronicMailAddress in WFS capabilities
Merge remote-tracking branch 'upstream/master'