Instead of #define DEBUG, we now prefer to use either verbose levels
or, when needed, NDEBUG. Each Makefile was modified to be able to pass
-D NDEBUG to the compiler (but the corresponding lines are commented),
except in the modules where assert is never used, in which case the
Makefile passes -D DEBUG.
Long story short: to totally disable debugging code, comment-out the
"-D DEBUG" lines and uncomment the "-D NDEBUG" lines, in every Makefile.
-lrt is now added as needed in each module Makefile, but not directly in
the library. Furthermore, the Makefiles add -lrt only if the platform is
Linux.
Matteo Cypriani