Break #signature out into own method for perf
Break #signature out into own method for perf

As calculating the signature requires reading the whole file, this won't
be a constant time operation. Therefore, be more lazy about it and only
calculate it when necessary.

mdkalish/minimagick,imton/minimagick,kim-company/minimagick,sdrew/minimagick,cartermarino/minimagick,minimagick/minimagick,n0nick/minimagick,tuanmai/minimagick,minimagick/minimagick