liq| shadergraph|: phong1.colorR --> liquidShader.frequency
liq| shadergraph|: add plug's children to validConnection - 1, + class ShaderConnectionMap
liq| shadergraph|: add plug's children to validConnection - 2, + add plug's children
liq| shadergraph| test|: liquidShader.frequency is both Input and Output
liq| shadergraph|: +ConnectionType{ CT_In, CT_Out, CT_InAndOut }
liq| shadergraph|:  liquidShader.frequency is both Input and Output.
Output the InAndOut parameter in RSL shader as output parameter.