fix import backup memory

git-svn-id: https://svn.code.sf.net/p/desmume/code/trunk@4879 5577840e-afb3-4e59-9ef3-2b7f898b1952
- optimizing reads/writes NAND backup data.

git-svn-id: https://svn.code.sf.net/p/desmume/code/trunk@4880 5577840e-afb3-4e59-9ef3-2b7f898b1952
fix write backup bug introduced by [r4880];

git-svn-id: https://svn.code.sf.net/p/desmume/code/trunk@4881 5577840e-afb3-4e59-9ef3-2b7f898b1952
- add SPU synchronization mode and method to command line;

git-svn-id: https://svn.code.sf.net/p/desmume/code/trunk@4882 5577840e-afb3-4e59-9ef3-2b7f898b1952