Adding a new source file inside a directory "dirname"
In order to be treated properly by the ABINIT build system, a new source file should be declared in the file abinit.src of the same directory (just one line to be added per new file, rather self-explanatory).
Then, in order for the make to work :
(1) if the developer has the autotools working on his computer, he should
issue */*/makemake, then configure and make
(2) otherwise, the developer should modify by hand the Makefile.am file
of the directory in which the file is placed (just one line to be added also),
then issue make.