Plugins not properly removed when unloading

When a plugin is unloaded, it's div (tab-content) stays in the DOM tree in minerva-plugin>tabView>tab-pane. This is a problem when the plugin is reloaded again because only one header exists and the old tab becomes the active one.

Another issue related to this is that when, e.g., the guide plugin is unloaded and the exploration plugin is loaded, just the interface of the guide plugin appears (because the unremoved guide plugin page becomes active) but the header says EXPLORATION.