Merge pull request #13 from tlocke/trunk

Merge PR to improve numeric_send and handle scale on decimal objects property
Merge pull request #14 from tlocke/trunk

Merge test cleanup and fixes related to timezone sensitivity
Merge pull request #15 from tlocke/trunk

Performance improvement for numerics
Fixed empty array bug

This fixes bug #10. Also added a test.

Tidied up code using pyflakes and pep8.