- Moved (u)mount prototypes from unistd.h to sys/mount.h.

- Prepared mount system call to accept multiple mount flags
   instead of just read_only (however, it remains backwards
   compatible).
 - Updated the man mount(2) to reflect new header file usage. 
 - Updated badblocks, newroot, mount, and umount commands to use the
   new header file.

commands/simple/badblocks.c

@@ -25,6 +25,7 @@
 #include <minix/type.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <sys/mount.h>
 #include <dirent.h>
 #include <stdlib.h>
 

commands/simple/mount.c

@@ -6,7 +6,7 @@
 #include <stdlib.h>
 #include <dirent.h>
 #include <string.h>
-#include <unistd.h>
+#include <sys/mount.h>
 #include <fcntl.h>
 #include <minix/config.h>
 #include <minix/const.h>

commands/simple/newroot.c

@@ -8,7 +8,7 @@ Replace the current root with a new one
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
+#include <sys/mount.h>
 
 int main(int argc, char *argv[])
 {

commands/simple/umount.c

@@ -13,6 +13,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/mount.h>
 #include <stdio.h>
 
 _PROTOTYPE(int main, (int argc, char **argv));