--cacert option is not used.

1. An environment variable named CURL_CA_BUNDLE may contain the full file
name to the file.

2. On Windows, the cert file may be named curl-ca-bundle.crt and put in the
same dir as curl is located (or the CWD) and curl will then use that file
instead.

USE_SSLEAY variable

were used

proceed fine with the already existing options, just having a different
internal library default for capath.

working for "IPv6 enabled" libcurls yet, but should be pretty easy for
someone to adjust.

Keith MacDonald found it.

so we need to hack around it when not there

ones themselves if they need to prevent this.