Update m3u/*, provider/*, tag/*.
Update provider/*, tag/*.
Merge branch 'gui'
Update provider/*, m3u/*.
GUI: add 'FileSave' menu item & button.
GUI: add 'FileClear' menu item & button, add 'Gtk.Statusbar', add columns to Gtk.ListStore & Gtk.TreeView.
Merge branch 'gui'
GUI:  add info to 'Gtk.Statusbar' about uniq values in columns.