Bug 7725: AAP with prefix 0.0.0.0/0 not supported in ACL

Bug 7725:  AAP with prefix 0.0.0.0/0 not supported in ACL

+ Added a check. In case of 0.0.0.0/0 prefix, program flow with just "ip"
match skipping the ip-prefix (0.0.0.0/0).
+ This method is called to configure flows both in table 40 and 251.

+ Handled below issue:
  - Create VM1 & VM2 with AAP 0.0.0.0/0 and default SG.
  - Create VM3 with default SG without AAP.
  - Delete VM2. Observe that +new+trk flow configured for VM2's 0.0.0.0/0 AAP
    prefix gets deleted (related to remote SG) in 252 table even though VM1 still
    exists.
    Flow: cookie=0x6900000, duration=4737.343s, table=252, n_packets=0,
    n_bytes=0,
    priority=61010,ct_state=+new+trk,ip,metadata=0x10000000000/0x1fffff0000000000
    actions=ct(commit,zone=5000),resubmit(,220)

+ Earlier flow priority was generated/used based on SG rule UUID. The
  above case was not handled with this approach.  So, with this fix now
  every ct_state=+new+trk flow will have a unique flow priority within table.
  Flow priorities are generated based on flow ID.

+ For every switch, two ID pools (one each for ingress and egress) are
  maintained which increases the availability of flow priorities.

Change-Id: I646312e1324267913cbb2865a1a8164b23b40372
Signed-off-by: Somashekar Byrappa <somashekar.b@altencalsoftlabs.com>
Signed-off-by: Sam Hague <shague@redhat.com>