[XNIO-229]: Adding support for more expressions in defining cipher suites

Now you can use the openSSL syntax to define which ciphers to use and also redefine the default cipher suite.
Jira: https://issues.jboss.org/browse/XNIO-229
It is only pollution if the classes are public, because that becomes API that I must support forever (or at least for a very long time).  I do not want to increase API surface area other than the option itself, if possible.  I'd rather see these classes in the org.xnio.ssl package.