[QGIS-Server] FIX 10489 QGIS Server getcapabilites response is not WMS compliant

To be fully compliant with WMS 1.3.0 standard, I propose to add :
* SLD namespace for GetLegendGraphic element
* schemaExtension.xsd distributed with QGIS-Server for GetStyles and GetPrint
* GetSchemaExtension to retrieve schemaExtension.xsd like MapServer

The solution was inspired by
 http://demo.mapserver.org/cgi-bin/wms?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetCapabilities
And the standard description
Styled Layer Descriptor profile of the Web Map Service Implementation Specification
http://portal.opengeospatial.org/files/?artifact_id=22364
[QGIS-Server] Clean GetCapabilities

Remove GetPrint request and ComposerTemplates from GetCapabilities for a better interoperability
Update Grass7Algorithm.py

GRASS GIS 7 update: dsn -> input|output as per http://trac.osgeo.org/grass/browser/grass/trunk/lib/gis/renamed_options
Merge pull request #1715 from rldhont/server_wms_getcapabilities_compliance

[QGIS-Server] FIX 10489 QGIS Server getcapabilites response is not WMS c...
Clean up QgsMapLayer scale based visibility api
[FEATURE] Evaluate expressions entered in QgsDoubleSpinBox

Allows entry of QGIS expressions into the spin box. The expression
is evaluated on enter or loss of focus and then discarded.

(refs #10544)
Flip all composer double spin boxes to QgsDoubleSpin (refs #10544)

Add clear buttons to applicable properties.
Also evaluate expressions entered in QgsSpinBox

and flip all composer spin boxes to QgsSpinBox (refs #10544)
Flip remaining symbology spinboxes to QgsDoubleSpinBox
Flip all labelling spin boxes to QgsSpinBox/QgsDoubleSpinBox
Merge pull request #1720 from neteler/patch-6

[processing] Update Grass7Algorithm.py
[processing] load documentation from online QGIS User Guide
remove debug code
Add support for map rotation (hub #9330)

Includes widget to show and set map rotation.
Handle rotation in vector and raster renderers.
Ensure correct behavior of panning and zooming actions.

Drop compile-time defines for ARM and ANDROID, leaving only
the qreal based function to transform in place.

Update expected test results after eye comparison.