Generate the local-kyua script

local-kyua is a wrapper script to run the just-built kyua inside its build
environment.  This is very useful during development, as it makes it possible
to execute kyua without having to install anything.

Should have done this eons ago as I have been manually typing various forms
of this on the command-line ad nauseam...
Very belatedly add 2014 to the copyright notice
Ensure tests succeed when 'ulimit -c 0'

If the user has disabled the ability to generate core dumps, we shall not
fail tests.  Instead, we have to mark them as skipped accordingly.

This is to support my/the use case in OS X where dumping core apparently
takes forever and it's just easier to disable cores when running our
test suite...