[PATCH] dm: ioctl: add noflush suspend

Provide a dm ioctl option to request noflush suspending.  (See next patch for
what this is for.) As the interface is extended, the version number is
incremented.

Other than accepting the new option through the interface, There is no change
to existing behaviour.

Test results:
Confirmed the option is given from user-space correctly.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>