Get ISPN cache to work correctly for REST

REST api was using incorrect cache name - so used cache was not
preconfigured at all, thatswhy cache entries never expired. Now, we'll
deploy rhqRestCache which is preconfigured with lifespan=15m and
max-idle=5min. This means, cache entry will be dropped and refreshed every
15minutes no matter how often is accessed and also if not accessed for
longer than 5minutes.