Minor improvements to SSL how-to.
- Hilite keystore type (JKS vs PKCS12) to lessen confusion
- Recommend to explicitly specify a protocol implementation when using SSL, instead of "HTTP/1.1"
- Update examples to use explicit protocol implementation instead of "HTTP/1.1"
- Remove BIO protocol from sample, add NIO2.
- Remove example of setting SSLEngine="off" with APR. It makes no sense on this page as here we are enabling SSL, not disabling it. The "off" value is documented elsewhere.
- The "8443" is not the default value for a port, as far as I know. One has to explicitly configure it.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1637695 13f79535-47bb-0310-9956-ffa450edef68