What's new?

That's again the large update. Completely renewed connection/expression mechanics.

Core

RuntimeAttribute and RuntimeModule classes instead of previous AttributeWrapper and ModuleWrapper.
These classes should be used while working with Modules and Attributes in scripts.
Connection and expression are evaluated on demand by RuntimeAttribute.pull/get or by RuntimeModule.ch.
Basically, it's like pull/push mechanics here. It results in more adequate behavior which can be used in interactive tools.
Expression is always evaluated on top of a connection.
Consistent API across widgets and the code.
You can use the same functions in widgets as you use in the code (like ch, module, copyJson, etc).
Widgets API.
Widgets can expose own API which can be used anywhere in code.
For example, curve_evaluate, listBox_selected, etc.
This API is used for autocompletion as well.

Refactor json widget, fix bugs and make it more stable.
Widgets support self.executor for evaluating python code within a proper context (API).
Widgets with code editor use correct autocompletion.
comboBox eliminates duplicates.
listBox uses roles for items and supports multiple selection. It's much more interactive now.
radioButton refactor.
vector widget supports a custom dimension, column count and precision.
fix curve widget somethingChanged emits(on release button) and zero division bug.

Evaluate/Clear expression menu for attributes.
Highly reworked widgetOnChange and updateWidget. Now it's more suitable for interactive tools.
Update style for attributes with connection/expression.
Fix bug in dropEvent for modules! Also it always generates unique names for modules.

Update example.xml with the latest features.
add runStandalone.py for running RigBuilder outside of DCC with a correct stylesheet.