set default focus and default button for edit window

set default focus and default button for edit window

this patch sets following defaults for the edit window:

defaultFocus: 'field'

sets the focus on the first field it finds in its child items,
works for most edit windows, so that the cursor stands in a
textfield, or on a checkbox

defaultButton: 'submitbutton'

so that when someone presses enter, we submit the form

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>