Merge pull request #11 from eggrobin/master

Catch up.
Vector space spec for R3Element.
R3Element spec.
Too tired to work on that today.
Forgot to save... :-p
Edited some comments.
'Frame' makes more sense than 'space'.
Tensor products with 1d dimensionful vectors make sense, factoring ArcTan.
Define the specialisations.
Started writing implementations, tests, random stuff...
R3Element implementation.
const-correctness, separate implementations for constructors.
the hobgoblin of little minds.
No whitespace at end of line.
Google C++ styleguide spacing compliance.
Implement * and /, both dimensionful and dimensionless.
Inner product spec.
Wedge spec.
Renamed unit test.
const& all the things.