Updates to demo programs, no longer needed ldl.
Minor updates to tests and demos shell scripts.
Simplified check macro.
Minor updates, fixed several compiler warnings.
Completely rebuilt Makefile from the ground up, added Module.mk

The new Makefile is now simpler, cleaner, and more modular. It supports
two build types: one standard development build, invoked by ‘make’
alone, which also runs tests and demos after compilation; and a ‘lib’
build type, which just produces a production version of the binaries.
Also added was the Module.mk file, which describes several pre-reqs for
using cdevutils, see file for documentation.
Moved python plotting script to demos directory.