New: Currency, formatted numbers and HTML numbers sort types built in

- This commit sees the number of built in type detection and sorting
  functions increase to cover the most common cases of use of plug-ins
  for DataTables (witht he exception of dates, for which a new first
  class plug-in will be created). Specifically, DataTables now has built
  in support for:
  - Dates (Date.parse())
  - Numeric sorting
  - Formatted numbers sorting (including currency and thousands
    seperators)
  - Numbers wrapped in HTML (link tags for example)
  - Formatted numbers in HTML
  - HTML

Although the numeric sorting plug-ins could have been collapsed down to
just two plug-ins (rather than 4) I decided to do it this way to allow
type based filter formatters to be used with the formatted number types
to allow search for "100,000" or "100000" to match the same data. This
is not built in, but it is possible (and might be in future).

- The goal with these additional functions is to enhance the abilities
  of DataTables out of the box to cover the most common cases for data
  usage - DataTables is all about making data in tables more accessable
  after all! The size cost is ~300 bytes for these additional functions