Squashed commit of the following:

commit 8bb96836ccf1c6f098cb963425979d4c0f837ed5
Author: RC <ramc@thoughtworks.com>
Date:   Wed Jan 23 16:51:58 2013 +0530

    RC | Including the namespace for Decimal

commit 90e8c82ea9712973f118c6cff1c052ce3f18a291
Author: RC <ramc@thoughtworks.com>
Date:   Wed Jan 23 16:12:43 2013 +0530

    RC | Adding support for postgres::numeric data type
no need to include DataMapper nor use the full name
keep lines shorter than 78 chars
RUBY