Allow expanding collection properties

[zspitz]

Properties that return collections should expand to a full datagrid of those items, if they have multiple properties; or a single column if a collection of scalar values.

[zspitz]

Each such collection should return its elements as a string[][], or perhaps a 2D array.

For WPF datagrid binding, a jagged array is probably better.

[zspitz]

We still need to handle an infinite sequence. Perhaps a fixed limit of 100 items?

[zspitz]

I'm not sure how to do this:

1. How do we handle instances of multiple types? An ArrayList or List<object> could contain multiple types. Even in a List<T>, there could be derived types.
2. The value at the property could be a never-ending sequence.

I think I will leave this for now.

[zspitz]

Perhaps something like this:

1. Create a dictionary / property bag for each element in the collection.
2. Use StringValue to render the property values for each instance.
3. Construct a custom type descriptor from the superset of all properties