Updated `share/examples/siterc.eg': Mac OS X

More useful aliases ready for use for Mac OS X users.
Updated `Makefile': development helper targets
Updated `.travis.yml': travis-ci matrix, rng, apt

Split out the various modules into independent travis-ci matrix items;
this way it is easy to see the health of each module without having to
read the actual output of the unit test.

Install from `share/unit/apt.conf' to prevent user-interactivity.

Install from `share/unit/rng-tools' to speed up RNG; this doesn't
currently work in the Travis CI environment for some reason.

Added coreutils to the packages list for `dd'.