[redux-devtools-inspector] Diff for Dates doesn't work

[zalmoxisus]

As discussed in zalmoxisus/redux-devtools-extension#468 (comment), Diff tab shows no changes for Dates, except when the type is changed from/to another. According to jsondiffpatch, it should be supported.

[agalazis]

I think there is a similar issue with sets as well