Use the xml property instead in IE for serializing XML.
The xml_eql tests were failing in IE9 on a difference between null and an
empty string for namespaceURI of attributes, this difference is not
relevant to our testing so make sure we ignore.
This adds a parser (read/write) for GML v2 and v3. GML v3 is limited to the
simple features profile of GML 3.1.1, just like OpenLayers 2 was. This will
be the basis for the WFS parser, but it only makes sense to continue this work
once feature modification (insert, update, delete) is in place in ol3. So the
WFS parser will be another pull request.
This adds ol.parser.ogc.KML which can be used to read and write KML documents.
NetworkLinks are retrieved asynchronously.
Current caveats of the implementation are:
* LabelStyle not yet implemented. Missing support in renderers.
* When using shared structures the parser needs to be configured with
dimension 2.
* We need a better way to disable fill, currently we use opacity as a
workaround.
* We cannot really roundtrip documents, since some of the info is not
preserved in the ol structures. But we can write out most of the important
info.
