LoadCAPath does not work with standard OpenSSL format capath

LoadCAPath() currently attempts to load every file in the given directory as a PEM, or fails with a message "Error loading CA Path: Couldn't parse PEM in:" on the first file that is not a PEM certificate. The standard naming format for CA certificates in the directory is `.N` where N starts from 0 and goes up, and a corresponding `.rN` for CRLs from the same CA. There may also be other files in the same directory. I didn't find a good web reference documenting this, but someone complaining about it made an [openssl issue](https://github.com/openssl/openssl/issues/1701) describing the layout and the response was this was the way it it has always been.

I am especially troubled by the fact CRLs are not supported, because of the security implications.

Related issues: #8, #10