Installation of GNUPlot 5.4.3 on Linux with png/jpg export support

We need to install libpng and libgd before the compilation of gnuplot-5.4.3

We can install libpng using yum install

yum install libpng-devel

The libgd-devel package provided by yum is not compatable with gnuplot-5.4.3 on the aws-linux-2,
we download and compile the officially new version.

wget https://github.com/libgd/libgd/releases/download/gd-2.3.3/libgd-2.3.3.tar.gz 
tar zxvf ./libgd-2.3.3.tar.gz
cd libgd-2.3.3
./configure
make
sudo make install

Then compile gnuplot.

cd libs
wget https://sourceforge.net/projects/gnuplot/files/gnuplot/5.4.3/gnuplot-5.4.3.tar.gz
tar zxvf ./gnuplot-5.4.3.tar.gz
cd gnuplot-5.4.3
./configure
make
sudo make install