Virtual CSW endpoints

[josegar74]

Add the capability to have custom CSW entry points that applies extra criteria to the CSW request.

A new CSW service entry point is defined using the following syntax:

<service name="csw-with-my-filter">
       <class name=".services.main.CswDispatcher" >
               <param name="filter" value="+inspirerelated:on +themekey:environment"/>
       </class>
</service>

The "filter" parameter value is the filter to apply to Lucene query using Lucene query syntax (  http://lucene.apache.org/java/2_9_1/queryparsersyntax.html). Allows OR and AND operators.

Adding new services require a restart of the application.

[josegar74]

Added updated patch including updated manual

[josegar74]

Updated patch fixing service end-points in capabilities document and documentation section on how to configure using overrides feature