Removed: bScrollInfinite and iScrollLoadGap

- The infinite scrolling feature of DataTables is inadequate as a
  solution for the problem it is trying to solve as it introduces a
  number of compatiblity issues with the rest of the API parimarily
  due to the fact that it "tricks" the rest of DataTables into drawing
  just a small proportion of the table, leaving the elements which are
  currently in place. This means that DataTables doesn't realise that
  the table has additional rows at the top of the table, thus breaking
  numerous interactions with the API and confusing developers. As such,
  its a poor feature that is just taking up space and could be done much
  better externally.

- I will write an infinite loading feature for DataTables in future for
  users that do what to use this ability - there is nothing stopping a
  simple scroll event being attached to the scrolling element and
  calling the rows.add() function. This is exactly what the new plug-in
  will do.

- Scroller is a much better solution for defined length tables.
Removed - bAutoCss and refactor scrolling functions for size

- The bAutoCss parameter is not one that I've ever actually seen used,
  so I've dropped it out here to reduce complexity. It was only useful
  for making the scrollbars always visible on the table, which can just
  as easily be done with `div.dataTables_scrollBody { overflow: scroll
  !important }` since that will take a heigher priority that the
  DataTables appled style.

- The moster _fnFeatureHtmlTable and _fnScrollDraw functions have been
  refactors, saving around 1.5K in size (in the minified file)