Clean

Created this branch to provide a clean repo that reproduces the mapping of small molecule binding to Pfam domains. A summary of the changes below:
 
* I have pulled all necessary functions into the masterscript. 
* Tables are not exported into a database.
* Queries have been changed where necessary to fit chembl_19 schema.
* Filtering of valid activities is done on pchembl value, rather than the collection of activity types used in the publication commit.

If you pull this branch, you get a straightforward version of the mapping adapted to releases >= chembl_19.

A few things are up for discussion, eg limiting mapping to human proteins.