Add a third sidebar on the right.
Implement a basic song info pane and attach this to new sidebar.
Show artist, title and provider in the text view.
Expand pragha-plugin-macros.h to alow publics configurable plugins.
Move some code to their own file..
Move threads to getting album art, lyrcis and artist bio on their own files.
Fix some years copyright..
Remove the pane from sidebar when close the plugin.
Hide sidebar when remove your last pane..
Fix some guard includes.
Save and restore second sidebar position..
Wait five seconds before search any song info.
Organize the song-info plugin code a bit.
Add pragha_songinfo_pane_clear_text()
Attach filename to threads to compare it with the current song when finish this.
Reduce to one seconds the timeout before search info.
(Five seconds is almost obligatory on lastfm. Here no. and it is annoying!)
Show a message to indicate that are searching.
Fill the library and the playlist after starting the rest to avoid lags..
Not launch any thread if the pane is not visible...
Update the pane when change the type required or visibilty changed..
Turns PraghaSidebar a GObject.
Hide the menu option to show/hide the second lateral pane when is empty.

TODO/FIXME/HELP: I have problems saving the visibility of the sidebar.
Disconnect two preferences signals.. Fix a crash!.
Remove binding to secondary-lateral-panel setting before remove the plugins.
Hide the menu option to show/hide the second lateral by default.