reverted back AppenderRef to appender-ref in log4j-1.2 and logback config files (and some log4j2 performance test config files), also fixed closing </Configuration> tag to lower-case </configuration> in logback config files

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1520863 13f79535-47bb-0310-9956-ffa450edef68