Fixed TimedCache to be mt-safe, also renamed it from TimedHasMap

lib/concurrentlinkedhashmap-lru-1.2.jar

lib/jython-2.5.2.jar

src/main/java/net/floodlightcontroller/core/IOFSwitch.java

.../net/floodlightcontroller/core/internal/OFSwitchImpl.java

src/main/java/net/floodlightcontroller/util/TimedCache.java