add a descriptive title to delete instance view

When the delete view is displayed, the title was "Undefined Server" which is confusing. This patch will display "Delete 'VM Name'" similar to the migrate view.

https://drive.google.com/file/d/0B9DbsE2BbZ7uVEVwLUJnVXRBb0E/edit?usp=sharing

Signed-off-by: Tyler Baker <tyler.baker@linaro.org>