Plot CCS waveform with analyze_ccs command

Builds earlier than 19.12-294_148:
command: analyze_ccs -verbose -comp_nldm 2 -gui 0

Builds latter than 19.12-294_148:
command: analyze_ccs  -comp_nldm 2 -report_log

### command: gnuplot -p gnuplot.cmd
### load waveform data from files ###

waveform0 = 'slew_0.002825_load_0.000183/waveform_simulation.txt'
waveform1 = 'slew_0.002825_load_0.000183/waveform_CCS.txt'
set multiplot layout 2,1 rowsfirst

### --- sub-figure 1: current

set xlabel 'time'
set ylabel 'current'
set grid
# set xrange [0:2e-10]
set datafile missing "NaN"
plot waveform0 using 1:2 with lp lc 3 pt 4 t "curr-simulation", \
       waveform1 using 1:2 with lp lc 4 pt 5 t "curr-CCS"

### --- sub-figure 2: voltage
set xlabel 'time'
set ylabel 'voltage'
set grid
# set xrange [0:2e-10]
set datafile missing "NaN"
plot waveform0 using 3:4 with lp lc 5 pt 6 t "volt-simulation", \
       waveform1 using 3:4 with lp lc 6 pt 7 t "volt-CCS"
unset multiplot