2.6.27+ portability changes

- Added SPL_AC_3ARGS_ON_EACH_CPU configure check to determine
  if the older 4 argument version of on_each_cpu() should be
  used or the new 3 argument version.  The retry argument was
  dropped in the new API which was never used anyway.
- Updated work queue compatibility wrappers.  The old way this
  worked was to pass a data point when initialized the workqueue.
  The new API assumed the work item is embedding in a structure
  and we us container_of() to find that data pointer.
- Updated skc->skc_flags to be an unsigned long which is now
  type checked in the bit operations.  This silences the warnings.
- Updated autogen products and splat tests accordingly

configure.ac

@@ -68,6 +68,7 @@ SPL_AC_KMALLOC_NODE
 SPL_AC_MONOTONIC_CLOCK
 SPL_AC_INODE_I_MUTEX
 SPL_AC_DIV64_64
+SPL_AC_3ARGS_ON_EACH_CPU
 
 TOPDIR=`/bin/pwd`