Added echoserver demo app.
More minor improvements of code.
Include terminating zero in size descriptions.
Make stuff build.

Unfortunately, I tend to forget to uninstall the package. Therefore,
stuff gets picked up from /usr/local when it should've been picked up
from the source tree.

Note that make distcheck is broken now. I still haven't grasped the
finer details on how to use top_srcdir vs. top_distdir. I just don't get
it.