In 14.04 Gnome Classic, how to add icons to panel?
To add icons or app launcher on panel key combination is windows button + Alt + Right Click. A drop down will appear with options to Add to Panel, Properties, Add panel etc.
Install gnome-session-flashback.
Using either synaptic or type in the terminal sudo apt-get install gnome-session-flashback
Besides install Metacity. Now log-out and choose from the log-in menu a flashback version, and you can add launchers to the menu bar by alt-right click.