Fixing the REST API to account for hierarchical counters
More unit tests.

of performace of updates. Introducing hierarchical counters, counter metatdata
and finer-grained handling of counter flush. Added unit tests and changed some
of the API calls

OrderedCollection is a marker interface that extens Collection. It
simply clarifies that the Collection has a well-defined iteration oder
although the interface itself doesn't specify the order. It's used to
return ordered PortChangeEvents

Topolgoy: don't remove ports the collection returned by the switch.  Make BVS port names case-insensitive

[BVS-498] Uplink port prefixes can be specified in bigfloodlight.properties.  This prefixes will be used for classifying a port as an uplink port, thus autoportfast will not be used on those ports.

- Simple interfaces and a syslog implementation for notification.
- Post notification for switch disconnect, link add, link update or link rmeove.

Remove source and destination port status from LinkInfo data strucuture.  The source/destination port info is also removed in model and CLI.

1. making the API more RESTful by replacing dashes with slashes and maintaining URI tree
2. adding REST calls for listing events and resetting events
3. completing the REST API for GET calls

Comaprisions of port names and retrivials from IOFSwitch.getPort(String)
are now case-insentivie. However, we still store port names with their
original case.

This is a quick-fix were we lower-case the port name before adding it to
the port map in PortManager. Should really use a map with
case-insensitive keys...

* add methods to update/compare the ports of an IOFSwitch
* use ImmutablePorts
* OFPhysicalPorts -> ImmutablePort in most test

  1. Moving debug event for switch connect/disconnect to Controller (from LinkDiscovery) to be consistent with Shudong's changes
  2. Bug fix in OFChannelHandler that was causing NPE
  3. Bug fix in DebugEvents that was ignoring flushNow directive in event registry
  4. Updated unit test

* Make all fields final or volatile
* Still not 100% safe (visibility): lastSeenTimestamp of the entities
  can be changed unsynchronized