Experimental RSX Debugger & minor changes

RSX Debugger:
Currently, it can preview the color buffers while the RSX Thread is
running, view and modify the render flags, and act as a memory viewer in
the RSX command buffers (no disasm yet). You can press F5, to update the
information (buffers, memory, flags, etc.) of the frame. There are *a
lot* of TODO's here that will be done in the future.

Minor changes:
*Added /dev_flash/ to VFS (required for cellFont in the future).
*cellMsgDialogOpenErrorCode implemented using wxMessageBox. The
information for each error code comes from PSDevWiki. There are lots
error codes missing.
*Updated sys_memory_get_page_attribute

Happy new year to everyone! :-)