New module with methods to copy data between databases
New module with methods to copy data between databases

It contains a unified implementation of copy_data(), merging
the various copies that were hanging around in the code.
It also brings in a new method to copy a single row with all its
dependencies.

Ensembl/ensembl-compara,danstaines/ensembl-compara,danstaines/ensembl-compara,Ensembl/ensembl-compara,Ensembl/ensembl-compara,danstaines/ensembl-compara,Ensembl/ensembl-compara,Ensembl/ensembl-compara,Ensembl/ensembl-compara,danstaines/ensembl-compara,Ensembl/ensembl-compara,Ensembl/ensembl-compara,danstaines/ensembl-compara