Thanks to A. Duret-Lutz for this page http://www.lrde.epita.fr/~adl/autotools.html and tutorial.
Download the autotools tutorial for knowning everything you need to make it work. 
It's a short reading.

Obviously Autotools (Autoconf, Automake, Libtool) need to be installed.

Put the Makefile.am, configure.ac and all_tests.sh in the cgreen top dir 
(the one with src/, include/ and test/ below)

This is the command sequence 
(commands are the lines beginning with $, being $ the prompt)

Run all the tools in the right order:
$ autoreconf --install
In case of problems add the --force option

If you don't specify --prefix and the dir after it below, stuff will be installed under /usr/local/ 
libs in /usr/local/lib and includes in /usr/local/include
So, use just one of the following commands:
$ ./configure --prefix ~/test    #for installing under ~/test/
$ ./configure                    #for installing under /usr/local/

Now let's go! make it
$ make

Check it with cgreen!
$ make check

Finally to install the package at the location specified above with ./configure
$ make install