Small GUI app for easy adding new appmenus for VMs

[joanna]

Generate new app menus for Dom0's start menu whenever the user installs new apps in a template VM.

[joanna]

Normally (in the case there is only one template in the system) the user fully trusts the template. This means the template's filesystem is not malicious, e.g. it's ok to mount it under Dom0, and the fs metadate will not be trying to exploit some (hypothetical) bug in the Dom0's fs module.

However when the user has more than one template, some templates might not be so trusted as others. In that case it's a security threat to attempt to mount template's fs under Dom0.

This means that if we don't trust the template *fully*, we cannot automatically update appmenues for this template!

[joanna]

I think the best solution would be to have just a few AppMenus? for each VM by default (just like we have now, starting from Beta 1), and one more Appmenu -- "Add more shortcuts...". When the user clicks this appmenu, it launches our app that communicates with an agent in the AppVM, who in turn parses the VM's /usr/share/applications directory and sends out the list of appmenus using a very simple (so, safe) protocol over xenstore (or qrexec). Then the user is presented with a list of Appmenus avilable for the VM and can check which one should be added to the menu.

[marmarek]

TODO: Trigger apmenus template update on package installation in TemplateVM (some yum trigger?)

[marmarek]

​http://git.qubes-os.org/gitweb/?p=marmarek/core.git;a=commit;h=f26acc13b6a116101284e1cdba5113e0211a4e28
​http://git.qubes-os.org/gitweb/?p=marmarek/core.git;a=commit;h=0682749990a6cc15c53fa718c026f82227e5ea70

Trigger added, menu item also.