Rib Waveguides

These are shallowly etched rib and rib-loaded strip waveguides

`RibWaveguideTemplate`	This waveguide is a (shallow etched) rib waveguide, with no specific bound in the slab.
`RibWireWaveguideTemplate`	This waveguide is a (shallow etched) rib waveguide, loaded on top of a (finite) strip wire.

Transitions

The following transitions to a rib waveguide have been defined:

`WireRibWaveguideTransitionLinear`	Transition from/to wire (deep etched) to/from rib (shallow etched) waveguides.
`WireRibWaveguideTransitionFromPortLinear`	Transition from/to wire (deep etched) to/from rib (shallow etched) waveguides.
`WireRibWireWaveguideTransitionLinear`	Transition from/to wire (deep etched) to/from ribwire (two-step etched) waveguides.
`WireRibWireWaveguideTransitionFromPortLinear`	Transition from/to wire (deep etched) to/from ribwire (two-step etched) waveguides.