WmsDescribeLayerModel is configured with the wrong type of proxy and misses a field
implement keepRaw for the attribute reader as well
Merge pull request #248 from bartvde/keepraw3

implement keepRaw for the attribute reader as well (r=@marcjansen)
Fix up requires section
Merge pull request #247 from bartvde/describelayer

Fixes for WmsDescribeLayerModel (r=@marcjansen)