Add a system property for cipher configuration. Add a "simple but safe" default cipher suite in catalina.properties. More complex cipher suites that have been proposed are either not as safe (weak ciphers present) or not very compatible according to my testing (OpenJDK has trouble, but the Oracle JVM fares better).

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1609689 13f79535-47bb-0310-9956-ffa450edef68