Integrate fuzz targets

[levirak]

Here's a pull request that I'm pretty sure accomplishes everything we talked about on the Monday team call. Hopefully my code is all up to standard.

[levirak]

I suppose a bit more of a comment is warranted. This integrates the OSS-Fuzz-targets repository into wolfSSL as a subdirectory. This allows us to implement a thin front end (fuzz/target_main.c in this PR) to run the fuzz targets for regression testing. It also has the side effect of making Google's OSS-Fuzz team happier with us and our integration.

On my end, all of the changes I've made don't break make check or make distcheck. In fact, it adds a script, fuzz/all_targets.test, to run during make check, and that seems to do fine.

I've never had to deal with the autotools before, so I'm interested to hear if there is a better/more robust way to do what I've done in configure.ac and fuzz/**/include.am.

[kaleb-himes]

Final review to be done by Todd Ouska before merging.

[wolfSSL-Bot]

Can one of the wolfSSL admins verify this patch?

[JacobBarthelmeh]

closing, not really relevant any more. We have external oss-fuzz tie in with cryptofuzz https://github.com/guidovranken/cryptofuzz and internal repo with additional fuzzing