Prior to this change, pinelog would always strip the directory prefix
from __FILE__, displaying only the basename.
This change adds the ability to check the full path passed to the
compiler, which may still be only a basename, but that's still fine.
Meson is a far more robust build framework, compared to autotools. This
greatly simplifies adding new features, since it's far easier to
maintain a set of meson.build files vs the autotools mishmash.
DEPRECATION NOTICE: Autotools based build is deprecated and will be
removed in the future.
nirenjan