webadmin: fixed edit icons in Setup Host Network dialog pt 3

Commit 83046362c5e727a80ede49075a630f9be9f82a31 broke the edit icon
fix from commit 6c03d4171c06328c665098c18145548aa13dcad8. Edit
icon was again misplaced. Fixed.

Also refactored the CSS -- grouped common classes for 'setup
network dialog', and removed patternfly hacks from
NetworkItemPanel.

Change-Id: I45d149db76d24b64ae9836c29ea7f03a5dcfcf7c
Bug-Url: https://bugzilla.redhat.com/1114991
Signed-off-by: Greg Sheremeta <gshereme@redhat.com>