Add GetContext request to QGIS WMS Server

This non standard request retruns the QGIS project as an OWSContext
document version 0.3.1.
This request gives more interoperability to QGIS Server that can be
directly used in client supporting OWSContext as config file.
This function has been funded by Ifremer.

src/mapserver/qgis_map_serv.cpp

@@ -550,6 +550,22 @@ int main( int argc, char * argv[] )
       delete theServer;
       continue;
     }
+    else if ( request.compare( "GetContext", Qt::CaseInsensitive ) == 0 )
+    {
+      try
+      {
+        QDomDocument doc = theServer->getContext();
+        theRequestHandler->sendGetStyleResponse( doc );
+      }
+      catch ( QgsMapServiceException& ex )
+      {
+        theRequestHandler->sendServiceException( ex );
+      }
+
+      delete theRequestHandler;
+      delete theServer;
+      continue;
+    }
     else if ( request.compare( "GetStyles", Qt::CaseInsensitive ) == 0 || request.compare( "GetStyle", Qt::CaseInsensitive ) == 0 ) // GetStyle for compatibility with earlier QGIS versions
     {
       try

src/mapserver/qgsconfigparser.h

@@ -45,6 +45,8 @@ class QgsConfigParser
 
     virtual void featureTypeList( QDomElement& parentElement, QDomDocument& doc ) const = 0;
 
+    virtual void owsGeneralAndResourceList( QDomElement& parentElement, QDomDocument& doc, const QString& strHref ) const = 0;
+
     virtual void describeFeatureType( const QString& aTypeName, QDomElement& parentElement, QDomDocument& doc ) const = 0;
     /**Returns one or possibly several maplayers for a given type name. If no layers/style are found, an empty list is returned*/
     virtual QList<QgsMapLayer*> mapLayerFromTypeName( const QString& tName, bool useCache = true ) const = 0;