Update README.md

Added supported operations
added describesite
Merge commit '6aa789e16c67771c6071f0f678bdea3a4d053c78'
Update README.md
updated version and added secure describesite test
Merge branch 'dev' of https://github.com/davetimmins/ArcGIS.PCL.git
Changed ISerializer to return IPortalRespnse to allow any response to be deserialized using composition rather than inheritence
In progress... not working yet, but tests not broken
Added constant values for operations
Simplified calling GET or POST
First test seems to work.
tidy up
Update README.md
Envelope criteria for FeatureServer and MapServer queries.
Retrieving points as points now instead of polygons, so Geometry is being populated correctly.
Update README.md
Refactored, plus added polygon test
Geometry queries - documentation.
Merge pull request #3 from leighghunt/dev_QueryGeometry

Adding Geometry criteria to queries
added constants for geometry types and spatial relationship types