SED-ML: plot log axes

[luciansmith]

Use the 'logX' and 'logY' attributes when appropriate:

From:

    <plot2D id="plot_1_task1" name="Figure 3b">
      <listOfCurves>
        <curve id="p1_curve_1_task1" name="Cancer" logX="false" style="style1" xDataReference="_1_task1" logY="true" yDataReference="C_1_task1"/>
        <curve id="p1_curve_2_task1" name="Immune" logX="false" style="style2" xDataReference="_1_task1" logY="true" yDataReference="I_2_task1"/>
      </listOfCurves>
    </plot2D>

BIOMD0000000751.omex.zip