Fix migration of Python nodes
Migration path update
Update "Select Face" migration to retain element
Fix magn1571: indexing into string does not work properly
Resync custom node defintion if it is updated before open .dyn file
Function definition in custom node

- Formula node now compiles to a function definition node, so it can't
be used inside custom node unless we promote the function definition
inside custom node to global scope.
- AstBuilder._CompileToAstNodes() promotes the FunctionDefinitionNode
returned from node.BuildAst() to global scope by notifying the graph
sync data about the function def node and not adding it to resultList.
- Now Custom node supports CodeBlockNode with function definition and
the Formula Node.
Merge branch 'master' of https://github.com/ikeough/Dynamo into Migration
Re-enable zero touch UI

For the brave
Add more test cases for string indexing
Force re-exec button added

Added an additional button that forces an engine reset before executing the graph to assist in debugging VM issues
Merge branch 'master' of https://github.com/DynamoDS/Dynamo
Update migration of XyzAverage
Added support to load custom nodes for recorded tests
Merge branch 'master' into MAGN-3185
Return this instance from method returning void

Fixes http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-2334
Deprecate CreateRevolvedGeometry node
Merge branch 'master' of https://github.com/DynamoDS/Dynamo into Migration
Migration path update
Update migration of GetFamilyInstancesByType
Update README.md