MemoryManagerService does not reset the used memory count to zero in clear

On invoking org.apache.directmemory.memory.MemoryManagerServiceImpl#clear the 'used' memory does not get reset to zero. Freeing up the pointer via free(Pointer) does update the 'used'. Similarly the clear operation should reset it to zero

[1] http://svn.apache.org/viewvc/directmemory/trunk/directmemory-cache/src/main/java/org/apache/directmemory/memory/MemoryManagerServiceImpl.java?revision=1494835&view=markup#l254