Tachiyomi: Old Dark Theme

[sleey]

With the new update we lost the old dark theme, why not make a new option rather than replace the old one.
I think some people will prefer the old one, like me.

[dkanada]

I actually like the new dark theme, except for the new navigation bar color. It blends in with the background color and looks odd in my opinion. Usually I don't mind small changes to a vanilla material design look but I definitely think that the navigation bar, toolbar, and status bar should stay a shade darker for contrast. Lots of apps will also merge the toolbar and status bar into one large bar with the same color, which I also think looks odd.

[inorichi]

I don't mind a new theme 'Dark blue' to restore the old toolbar color. Open for pull request.