Improve debugging experience for LINQ

[YohDeadfall]

While state machines are chained genetics, and it's possible to see what an observer is doing, it would be much better to provide information on more friendlier way. For example, an observer's ToString would provide only the base type name, input and output types. Anything else can be displayed using the debugger display attributes.

• Property debugging visualization (Improved debugging experience for properties #152)
• Collection debugging visualization
• Inspection of state machine chains (Added an ability to inspect state machine chains #151)
• Debugger visualizations for state machines

[YohDeadfall]

#148 provides a ground for custom debug views for stacked state machines.