JSON for in/of must be reviewed

[darnocian]

when doing a for loop over TJSONObject, the for in/of is not consistent with normal arrays and dictionaries.

normally, 'for in', will loop over the indices, where 'for of' will loop over the values.

Havn't tested exhaustively, but noticed that with the TJSONValue:

{
 "globals": [ 5,4,3]
}

and

<% for x in globals ; x ; betweenitems %>, <% end %>

should give

 0, 1, 2

but it gives:

 5, 4, 3

This is the behaviour of

<% for x of globals ; x ; betweenitems %>, <% end %>

[darnocian]

Creating a test, the enumerating over TJSONArray using 'of' is correct. When doing 'in', we need a fix.

[darnocian]

Making things consistent is actually a breaking change.