make more use of mkA() in interface.php

This change updates a few functions to output <A HREF...> through a call
to mkA() helper function.

* printObjectDetailsForRenderRack()
* renderRack()
* renderEditObjectForm()
* renderObject()
* renderIPSpaceEditor()
* renderIPv4NetworkAddresses()
* renderIPv6NetworkAddresses()
* renderNATv4ForObject()
* renderLocationPage()
* renderRackPage()
* renderLivePTR()
* printRoutersTD()
* renderCell()
* render8021QOrderForm()
* render8021QStatus()
* renderVLANDomain()
* renderVirtualResourcesSummary()
* renderEditVlan()