Refactored the way WTSI::NPG::Genotyping::Database::Pipeline handles
its dbfile attribute with respect to ini files and command line
arguments. The aim is to be clearer about what is happening during
object initialisation.
Merge pull request #206 from keithj/devel

Refactored the way WTSI::NPG::Genotyping::Database::Pipeline handles its dbfile attribute
Merge pull request #207 from wtsi-npg/devel

Refactor dbfile attribute in WTSI::NPG::Genotyping::Database::Pipeline