New - api methods: page(), page.info(), page.len(), draw()

- Paging control methods for the new API:
  - page() / page(n) - Get / set the current page
  - page.info() - Get information about the table's paging state
  - page.len() / page.len(n) - Get / set the page length

- Rewrite of core.page.js and core.length.js to be more space efficient.
  The functionality is identical to before, but now compresses much
  better (796 byte saving). The new paging API methods add only 614
  bytes (compressed), so overall a saving of 182 bytes, with the new
  functionality added by the new API.

- Start of draw methods for new API:
  - draw() - Draw the table. Need this to test the new paging methods
    since page() etc do not do a redraw themselves, you must call draw()
    when you are ready for the table to be redrawn now.