LOG4J2-531: fix PatternProcessor initialization, RollingFileManager initialTime, fix bug in DefaultRolloverStrategy that overwrote existing archive, emit debug/trace level status log messages

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1566302 13f79535-47bb-0310-9956-ffa450edef68