Replacing Header Icons and fix spacing

(cherry picked from commit 1b695d390fa41ce3d4a2ad1506121468a70488e1)
Signed-off-by: Jirka Kremser <jkremser@redhat.com>
[BZ 1127654] - Patternfly theme: various minor UI issues - window header icons, better icon for pencil (edit), fixing mouse cursor for header icons