New: DataTables events are now all bound to the `.dt` namespace

- This is a breaking backwards incompatible change - please be aware of
  this!

- DataTables fires custom events such as `draw` etc, but these events
  were in no way identifyable as eminating from DataTables rather than
  some other component, which can cause confusion and difficulty
  resolving bugs.

- As such, all DataTables events are now fired with the `dt` namespace -
  this means if you are currently using events, you must update your
  code to also use the .dt namespace. If you are already using
  namespaces, that's great, you can continue to do so as jQuery allows
  multiple namespaces, but you must still use the .dt namespace.

- This is a breaking change because the old behaviour was incorrect -
  i.e. this was a bug to be fixed, hence why we haven't gone through a
  deprecation cycle. The old events weren't well documented (only in the
  JSDoc generated docs and a few of my forum posts), whereas in 1.10
  they will form a key part of the documentation. As such, now is the
  time to get this right. This will be documented clearly in the upgrade
  notes.

- Discussion on this topic here:
  https://github.com/DataTables/DataTables/issues/245
Docs: Update event docs for the `dt` event namespace - ae0951b

- Examples all now use the `dt` namespace

- A note added to each event documentation page to state that the `dt`
  namespace must be used
New: Warning on generic Ajax error (404 etc)

- Previously DataTables would only show an error message if there was a
  JSON parsing error. However, if there was any other kind of error,
  such as a 404, it would just silently swallow the error. THink its
  best to show an error and a tech note.
Dev: Remove the static `construct` method that had been added as part of 1.10

- I added a static DataTable.on() method previously in the 1.10
  development for a single event called `construct` which would tell us
  when a table was constructed. But I've realise that since the events
  that DataTables' triggers bubble up through the document, that effect
  can already be achieved:

- Use:
  - $(document).on( 'init.dt', function ( e, settings ) { } );

- Rather than:
  - $.fn.dataTable.on( 'construct', function ( settings ) { } );

- No backwards compatiblity issues as the DataTable.on code was never
  shipped, its dev code only
Dev - examples: Update the example code to take account of the event
changes from: ae0951b, 694f129 and 1f561e3