Missing correlation display

[maciekjswat]

The correlation between the random effects, although defined in the ParameterModel such as in the attached, is not displayed, e.g.

        <!-- CORRELATION BETWEEN RANDOM EFFECTS -->
        <Correlation>
            <ct:VariabilityReference>
                <ct:SymbRef blkIdRef="model" symbIdRef="indiv"/>
            </ct:VariabilityReference>
            <RandomVariable1>
                <ct:SymbRef symbIdRef="eta_CL"/>
            </RandomVariable1>
            <RandomVariable2>
                <ct:SymbRef symbIdRef="eta_V"/>
            </RandomVariable2>
            <Covariance>
                <ct:SymbRef symbIdRef="rho_CL_V"/>
            </Covariance>
        </Correlation>

[Mihai Glonț]

reopened due to issues with taglib's stateful nature.