EASY: add logging to goblin

[m4b]

It's time to get Real Serious ™️ and add logging to goblin.

There are a number of places in goblin where things have "gone wrong", but not enough that we shouldn't parse.

Refactoring dyn to check the index of DT_NEEDED to fix a bug found while fuzzing, ref #27, we should continue parsing, but the client only receives a None, which is fine for clients, but we may also want to know why we received none, hence a warn! would be appropriate.

There are also many times when debugging, e.g., #28, I just need to see the execution state at the point of failure, which is precisely what debug! is for.

Steps

1. add extern log
2. add logs in various places, useful places. debug! for extremely verbose stuff, info maybe, and warn! where the binary is malformed some way, e.g., in first example.
3. add to PE
4. add to ELF
5. add to mach

[m4b]

logging is in place, now can slowly add logs where appropriate to places. PE is mostly done I think, minus the exports.

[m4b]

Meh; this is basically done; can implement as needed, where needed, e.g., like in #64