Need nominal C & Perl test suites

[d-lamb]

At the moment there is no way to see if changes to the code break something other than by checking for compiler errors or running one of the relaxation examples. A 'make check' C test suite and a 'make test' Perl test suite are necessary. Tests could come in multiple levels:

• Initialization and population of the basic Flux objects
• Operations on fluxons: adding & removing vertices, opening fluxons, adding fluxons to a world, etc.
• Comparison of forces to analytic solutions