Add correct support for getFeatureInfo.

getFeatureinfo needs information about what is shown exactly
on the screen to give the correct answers.

The search now include width, height, bbox and cql_filters.
Merge branch 'lizard5' of github.com:lizardsystem/lizard-map into lizard5

Conflicts:
	CHANGES.rst
Merge pull request #30 from lizardsystem/roland-popup

Proper getFeatureInfo support, which deals with zoomlevel.