added hill climbing sample and custom nodes needed for sample from post 4
changed package file to include custom nodes for sample in post 4
added a test that checks results of the recursive hill climbing using xyz distance to verify the correct result.
note that I was not sure on best practices for referencing samples and custom nodes needed to run the test so I referenced them directly from the samples and dyf folders.
changed custom nodes to use no python so this test does not time out.
added Rendering_hill_climbing_simple() test to the DynamoRevitTests.xml
add test case for migration class
Beginning refactoring visualization manager.
Merge branch 'ChocoButter-2Become1' into VizManager
Added migration functions

- CoordinateSystem transformations (after being added back to
ProtoGeometry.dll)
- Family type, wall and floor selectors
- Added a migration helper function to change both node name/type and
node nickname
fix bugs
Merge branch 'CrossFade' of https://github.com/Benglin/Dynamo into CrossFade
fix the bug at the string concat
Merge branch 'CrossFade' of https://github.com/Benglin/Dynamo into CrossFade
Merge branch 'ChocoButter-2Become1' into VizManager
Get Element Id and Unique Id on AbstractElement, add ApproximateAssertExtensions for comparing XYZ, Vector, Point approximately
Refactor Domain and Domain2D into Revit.Geometry namepsace, renamed DSCategory just to Category
Move Category node into Revit.Application
On second thought, let's put in Revit.Elements
Progress. Working with IGraphicItem.
Merge branch 'ChocoButter-2Become1' into VizManager
IGraphic item test working.
Updates to proto-geometry and protointerface because of missing file.