Added 2002 and 2006 datasets.
Added 2010 dataset (with line endings converted CRLF -> LF).
Parser.read(): read table into list.
Column re-alignment of 2002 and 2006 datasets.

I intended to parse this with a regex and avoid touching the original
data files, but it was either imperfect with a couple of false +ves or
too complicated accounting for these exceptions. I have therefore
resorted to ensuring there is 2+ <space> between each column (field
strings have <=1 <space> internally).

This is not the end of the world. The files are diff-able and a word
diff shows that none of the strings have been altered. It makes the
parsing regex a lot less convoluted and therefore simplifies the code.
Added an intermediate _parse_columns() method

The rationale here is to have an intermediate list of tuples
containing unmodified (non-whitespace) strings which can be
reconstructed to create something similar to the original file for
checking consistency in a unit test.
Merge branch 'dev' into feature/parser

'dev' now contains the dataset format adjustments required for the
parser to function correctly so these have been incorporated into this
feature branch for testing.
Altered the basic record parsing implementation.

Had a bit of a rethink, the table records are better represented a bit
more meaningfully as specialised objects. I still see value in
breaking this parsing process down into a multi-stage one for
testing/validation purposes so this just makes the code a bit tidier.
Forgot to import namedtuple object
Introduce a constants property to the parser.

Contains a list of physical constants derived from the table records.
The derivation involves some string replacement (to remove
cruft/non-parsable characters etc) and some type coercion. These are
stored in a named tuple the same as the records but of a
"PhysicalConstant" type and not "CODATARecord" type purely for
semantic reasons.
Added a version selection via init arg.
Blank line deletion.
Merge branch 'feature/parser' into dev

Basic parser implementation is complete, constants can be read from
the file and outputted in a basic list format as namedtuples. Datatypes
for the fields are sensible (string, float, float, string).

No modifications have been made to the Quantity name or Units fields,
for now they are OK as-is.