Man pages updates

Adapting the following manpages from sysconfig:
  ifcfg-bonding.5
  ifcfg-bridge.5
  ifcfg-vlan.5
  ifcfg-wireless.5
  ifcfg.5
  ifdown.8
  ifstatus.8
  ifup.8

Tweaking ifup script to follow what's in man pages.

Solution to the [Bug 855135] man wicked (8) refers to non-existing wicked (7) - see https://github.com/pwieczorkiewicz/wicked/blob/c9b693dde01d99e472db297fd241d2c0813559fd/man/wicked.8.in