lib/classifier: Support variable sized miniflows.

lib/classifier: Support variable sized miniflows.

Change the classifier to allocate variable sized miniflows and
minimasks in cls_match and cls_subtable, respectively.  Do not
duplicate the mask in cls_rule any more.

miniflow_clone and miniflow_move can now take variably sized miniflows
as source.  The destination is assumed to be regularly sized miniflow.

Inlining miniflow and mask values reduces memory indirection and helps
reduce cache misses.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>