C client SSL implementation: request for initial review

-  added a comment for `BIO_free()` in `riak_connection_free`, it will remain commented out
- once this is cleaned up a bit more, I'll submit an official PR
- you'll need the `autoconf-archive` package installed. If you are on OSX, I believe `brew install autoconf-archive` does the trick.

```
(cd test/ssl_tests && ./build_test_node.sh)
./autogen.sh
./configure -with-openssl=/usr/local/Cellar/openssl/1.0.1f
make
./riak_c_example --port 8087 -S -U foo -P bar -C ./test/ssl_tests/certs/cacert.pem --put --bucket TestBucket --key TestKey --value FooBar123
./riak_c_example --port 8087 -S -U foo -P bar -C ./test/ssl_tests/certs/cacert.pem --get --bucket TestBucket --key TestKey
```
Only tested on OSX at this point, Linux testing is next.

cc @javajolt @broach @bkerley