* - Extra method added to iterate over node data structure outside of the library
* - Added more robust context menu
* - Fixing crashes during node/connection removal
* Automatic type cast node insertation working in a basic manner
* Port paint fix to handle convertible types
* Code cleanup, documentation,, and minor fixes
* Fixing master merge
* Master merge fix 2
* Master merge fix 3
* Code style fixes
* Fixing logic error, where typecast node with the same input-output types were permitted
* Fixes based on @russelltg 's suggestions
* Got rid of unique_ptr static_casts
* Partial fixes from the code review
* Merging master into branch vol. 3
The CGO is requested in `NodeGraphicsObject::moveConnections` with the call stack:
```
Node::onDataUpdated
Connection::propagateData
Node::onDataUpdated
```
Which is called in createConnection
* Node validation and error display implemented
* Added option to iterate through nodes in the scene. (Useful to read out data from all the nodes, makes code generation based on the graphs easier.)
* Visual error fix for nodes that change size depending on input, plus minor styling and logic fixes in the example, based on the comments of @russelltg
* Validation extended to handle warnings, based on the idea of @russeltg ; Error display colors now come from the style system; Additional bugfixes
* DefaultStyle.json identation fix
* FlowScene.cpp identation fix
* Travis build test fix