Create SFFS library out of HGFS

This Shared Folders File System library (libsffs) now contains all the
file system logic originally in HGFS. The actual HGFS server code is
now a stub that passes on all the work to libsffs. The libhgfs library
is changed accordingly.

lib/libsffs/const.h

@@ -0,0 +1,16 @@
+#ifndef _SFFS_CONST_H
+#define _SFFS_CONST_H
+
+/* Number of inodes. */
+/* The following number must not exceed 16. The i_num field is only a short. */
+#define NUM_INODE_BITS	8
+
+/* Number of entries in the name hashtable. */
+#define NUM_HASH_SLOTS	1023
+
+/* Arbitrary block size constant returned by fstatfs and statvfs.
+ * Also used by getdents. This is not the underlying data transfer unit size.
+ */
+#define BLOCK_SIZE	4096
+
+#endif /* _SFFS_CONST_H */