Implement a rowbuffer cache, and do the google test

If use this cache, should add cache=1 to enable ROWBUFFERCACHE flag when compiling,
and should set its construct parameters in system.ini file.
Intergrate RBC class to CommandQueue and MemoryController class partitally
Change *cache* related name to *buffer* in RowBufferCache class
Merge branch 'rowbuffer_cache' into rowbuffer_buffer