plug in the url manglers with gwc's hook

GWC now has a hook for altering the urls that it generates. This plugs
into that hook, and delegates to the geoserver response utils chain,
which calls all the geoserver pluggable extensions.
added WMS and WMTS support for URL mangling
Fix for URL mangling base paths, and adding WMS and WMTS mangling
Merge branch 'master' into gwc-url-mangling-master
replaced hardcoded geoserver version number.
Added support for LayerGroup to the WMS GetLegendGraphic action
wfs capability extension point

Added an extension point for adding wfs capability extension elements
Added wfs inspire extension which demonstrates the use of said extension point.
Work is financed by IGN
fixed some bugs and added forceTitles legend option
Fixed version number reference to follow the project convention.
Improving range subsettting code and coverage response delegate class
Make WCS 2.0 work against both lon/lat and lat/lon oriented coverages
 Improved WCS 2.0 GetCapabilities output
Fixing dynamic dimension tests after changes to coverage delegate handlers
fixed layer, style and rule parameters size mismatch; fixed tests not running on linux
GEOS5547 - GSIP84 - LayerGroup: added Mode, RootLayer and RootLayerStyle. Updated WMS GetCapabilities and GetMap
 fix for GEOS-5537, Tiling artifacts with RasterSymbolizer using bilinear interpolation
Merge pull request #97 from simboss/master-upstream

 fix for GEOS-5537, Tiling artifacts with RasterSymbolizer
adding some required dependencies to groovy artifact
updating test case to add layer before layer group
some test cleanup, and some reorganization of files stored in data directory