Hide or reveal input/output nodes depending on workspace context
Cleaned up logic and extended for more general case
Revive unit tests for hiding/showing input and output nodes
Remove crufty check in CreateNodeInternal that prevent placement of Input/Output nodes
Fix for Node Preview size

Fixes an issue with the Node Preview, where the first time the preview
is generated, it's a small default size instead of the size it should
be.  This is evident on long preview boxes.
Revert "VMDataBridge - Passing information out of the VM mid-execution"
Merge pull request #1940 from DynamoDS/revert-1925-DataBridge

Revert "VMDataBridge - Passing information out of the VM mid-execution"
Merge pull request #1939 from dannypolkinhorn/master

Fix for Node Preview size
Merge remote-tracking branch 'origin/master' into Revit2015
Update README.md
Merge pull request #1937 from pboyer/IOHiding

MAGN-1314: Hide Input & Output nodes in Home Workspace
Add dynamic dispatch for Units on SetParameter.
Merge remote-tracking branch 'origin/master' into Revit2015
Merge branch 'Revit2015' of https://github.com/DynamoDS/Dynamo into Revit2015