Patch from Yann Morin to put BLKGETSIZE64 in platform.h had rather a lot of

Patch from Yann Morin to put BLKGETSIZE64 in platform.h had rather a lot of
fallout due to the #include <sys/mount.h>.  Removed that #include from various
applets and fixed up those that were unhappy when that #include was made
because they'd block copied stuff out of it.  (Sigh.)