Also, unread and date markers are now half-transparent based on their colors and not parent opacity. This is necessary to display a non-translucide tooltip.
Also, move the `DedupePlugin` to the prod-specific section. [Webpack doc](https://webpack.github.io/docs/list-of-plugins.html#dedupeplugin) itself recommends to not run this outside of production.
Note that this currently breaks cross-OS support of `npm run build`. This will be fixed in a latter commit.
