New Battery dedicated section

[andirsun]

How about build a new section to see the battery stats in the power switchboard.
We can get the history stats from the gnome-power-statistics and display in modern Gtk widgets
This is the first step in this direction elementary/panel-power#190
From this :

To something more modern like mac os does :

[cassidyjames]

This is being discussed at #156. Please use that issue for further discussion.