MapCache sends invalid WMS GetCapabilities

MapCache WMS cannot be used with some WMS clients because of some issues in the WMS 1.1.1 GetCapabilities response.

- Content-Type is text/xml instead of application/vnd.ogc.wms_xml. However, I do not know if this is so bad for the clients. Behaviour is the same for me than in the the closed issue #35.

- Service is advertising a group layer "rootlayer, but it cannot be used for GetMaps. because MapCache does not recognize such layer.
- Layers have only ```<Name>``` but not ```<Title>``` which is compulsory

Below is an excerpt of the MapCache demo service from MS4W 3.1.0beta1 installation on Windows.

```
<Layer>
<Name>rootlayer</Name>
<Title>no title set, add some in metadata</Title>
<SRS>EPSG:900913</SRS>
<SRS>EPSG:4326</SRS>
<SRS>EPSG:3857</SRS>
  <Layer cascaded="1" queryable="0">
  <Name>test</Name>
  <LatLonBoundingBox minx="-180.000000" miny="-90.000000" maxx="180.000000" maxy="90.000000"/>
  <BoundingBox SRS="EPSG:4326" minx="-180.000000" miny="-90.000000" maxx="180.000000" maxy="90.000000"/>
  <SRS>EPSG:4326</SRS>
  <BoundingBox SRS="EPSG:900913" minx="-20037508.342789" miny="-20037508.342789" maxx="20037508.342789" maxy="20037508.342789"/>
  <SRS>EPSG:900913</SRS>
  <SRS>EPSG:3857</SRS>
  </Layer>
</Layer>
```