Some improvements

[catborise]

Hi retspen,

Some usesul new improvements;

1. Show Interface ip address with the help of guest agent.
2. Add link state for instance network. Without removing interface, it could be down or up.
3. Guest channel add remove.
4. Show if guest agent installed or not. Connected or not.
5. Fix some bugs with cdrom&q35, qemu&kvm type selection, host interface config error prevents instance editing. it is fixed also...

thanks.

[retspen]

Thank you!