Mutation tests refactoring
Merge branch 'master' of https://github.com/DynamoDS/Dynamo

Conflicts:
	src/DynamoCore/TestInfrastructure/MutatorDriver.cs
Attribute class added
Merged few files from "Concurrent" branch for review
Included "SetTraceDataAsyncTask.cs" project in "DynamoCore.csproj"
Merge branch 'master' of https://github.com/DynamoDS/Dynamo into NewAsyncTasks
change start page's samples list box to treeView. Added show samples in folder
Merge branch 'master' of https://github.com/DynamoDS/Dynamo into treeView
Merge branch 'master' of https://github.com/DynamoDS/Dynamo into treeView
Change some code format, function name
added VMDataBridge to 2013 solution
Merge branch 'master' of https://github.com/DynamoDS/Dynamo into NewAsyncTasks
Added documentation for CompileCustomNodeAsyncTask class
Added documentation to "DelegateBasedAsyncTask" class
Migrate lacing in MigrateToDSFunction methods.
Merge branch 'master' of https://github.com/DynamoDS/Dynamo
Merge branch 'master' of https://github.com/DynamoDS/Dynamo
Merge branch 'master' of https://github.com/DynamoDS/Dynamo
@Benglin Here are some updates code according to your notes.

Brief changes description:
MutationTestAttribute was added to all mutation tests in order to distinguish Mutation tests classes from others in DynamoCore (it simplifies process of launching these mutation tests).
MutatorDriver class contains only basic methods for test launching, it also obtains all mutation tests from current assembly and runs them on the current workspace.
fixed watch node clear issue