Views: do not fire the "dirty" flag if there are no changes.

[klonos]

To reproduce:

1. Edit a view
2. Hit the "Change view name/description" button
3. Hit the "Cancel" button on the dialog that pops up (with or without editing any value)

Result: you are returned to the edit view UI with the "dirty form" message, even when nothing has actually been changed:

All changes are stored temporarily

Expected result: there were no changes, so the "dirty form" flag shouldn't have been triggered and no message prompting you to save or cancel should be shown.