Internal wrapper for creating trend and change-point plots
screen.frames.internal(input, mparam, mylab, DataType, maf, mmar, text, xaxis,
Year1, YearEnd, hyrstart)
metric time series
trend and change point info
y axis label
numeric indicating data type
mean annual flow series
plot margins
boolean indicating whether to add text
boolean indicating whether to plot the x axis
start year of original time series
end year of original time series
numeric indicating month for start of the hydrologic year