tests: Fix ovs-ofctl rule with importance test case.

Sort the flow dump results to always have them in consistent order.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
classifier: Integrate insert_rule() into classifier_replace().

insert_rule() only had one caller and this makes the code easier to
understand.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>