loading project with stopped studio needs better handling

[http://nedko.arnaudov.name/]

Tue Dec 14 15:05:42 2010: Load project request
Tue Dec 14 15:05:42 2010: -------
Tue Dec 14 15:05:42 2010: ladish_graph_remove_hidden_objects() called for graph '/org/ladish/Room1'
Tue Dec 14 15:05:42 2010: graph /org/ladish/Room1
Tue Dec 14 15:05:42 2010:   version 926
Tue Dec 14 15:05:42 2010:   persist: yes
Tue Dec 14 15:05:42 2010:   clients:
Tue Dec 14 15:05:42 2010:   connections:
Tue Dec 14 15:05:42 2010: -------
Tue Dec 14 15:05:42 2010: Loading project '/home/in0giro/casa/musica/progetti/in-giro/canzoni/a dim light/a dim light 2010.001' into room 'room 01'
Tue Dec 14 15:05:42 2010: Project 'a dim light 2010.001' with uuid 0bea1f65-99ea-4496-a87f-30e2885c984b
Tue Dec 14 15:05:42 2010: room port "audio_capture_1" with uuid f3b66bdf-eabd-4c73-969e-852a8f18db60
Tue Dec 14 15:05:42 2010: ERROR: callback_elstart: Cannot find room link port.
Tue Dec 14 15:05:42 2010: ladish_graph_remove_hidden_objects() called for graph '/org/ladish/Room1'
Tue Dec 14 15:05:42 2010: graph /org/ladish/Room1
Tue Dec 14 15:05:42 2010:   version 926
Tue Dec 14 15:05:42 2010:   persist: yes
Tue Dec 14 15:05:42 2010:   clients:
Tue Dec 14 15:05:42 2010:   connections:
Tue Dec 14 15:05:42 2010: ERROR: run: Project load failed.
Tue Dec 14 15:05:42 2010: load project command destructor

we could eventually just have a dialog box that says the
studio must be started first, or even better, prevent Projects from
being loaded when a Studio is not started (similar to how one cannot
save a Studio until the Studio is started).

Reported by Wayne on the mailing list. I can reproduce this with ae342e1ba9cba6911bf18d7469bcef1a77cda023

[http://nedko.arnaudov.name/]

I've reworked the menu in eaf2b0bd504a29695ec09fa1ed7a33ea5b858ea4 so that it is not possible to load project when studio is stopped.

[http://nedko.arnaudov.name/]

The context menu was not fixed. This commit adf0550947e02ec46e987a59516463ce5c43ddf3 should fix the context menu too.