Shielding VCL Rendering
Changed how shielding VCL is rendered
Backends with shielding enabled are now emitted in VCL using a custom 'shield' director type that omits the formerly-required backend definitions. The result is significantly fewer lines are used to emit a shielding configuration. This change may be visible in the VCL diff tool.
Prior change: Go SDK 0.1.7
Following change: Regular expressions in VCL
