Dylan/block load error handling

Recreation of pull https://github.com/duckduckgo/p5-app-duckpan/pull/56, resolving issue https://github.com/duckduckgo/p5-app-duckpan/issues/55. Now automatically calling installdeps when a module fails to locate a dependency. Reattempts load (once) after running. Easily extensible to handle additional failure paths.