Fix parsing for WCS 1.1.0 GetCapabilities from ArcGIS Server

ArcGIS Server generates an invalid GetCapabilities document for WCS 1.1.0. This patch fixes parsing these documents. Note that the XML is not properly formed, so supportedFormat and supportedCRS will not be available. This information is available from the DescribeCoverage document.

Test coverage of new code is also provided.

(Sorry that I cannot not fully squash the commits -- I did manage to reduce the number somewhat, but cannot get it lower than what is presented here.  The diff shows the changes I am proposing.)