Remove Diff monitor

[zalmoxisus]

Are there any advantages of using Diff Monitor since we now have Diff functionality in the Inspector Monitor?

There are some issues there solved by @jhen0409, but not sure how maintained the project is. To support it in future we'll also need to support theming there as suggested in #96.

[Koleok]

I don't think the diff monitor has enough to offer to really justify itself in light of the inspector

[jhen0409]

The Inspector has not yet implement some features, like alexkuz/redux-devtools-inspector#19 alexkuz/redux-devtools-inspector#20.

But I agree removing Diff monitor, I don't know they whether or not to continue to maintain project, if they don't fix these problems, it's not conducive to self-build for extension.

[zalmoxisus]

@jhen0409, while these features are present in the Log Monitor, that's not a problem. We want to have multiple monitors, each of them should be focused on solving specific problems.

[alexkuz]

Inspector now supports skipping and committing actions.

[zalmoxisus]

Removed in v1.3.0.