Merging postreleasefix/88 to master
Merging postreleasefix/88 to master

* postreleasefix/88:
  correct logic for picking up sample list
  re-add copyright line
  delete cached key _pairwise
  use all slice objects for getting vf objects
  add tests for fetch_by_VariationFeatures with use only VCF and use VCF and DB

willmclaren/ensembl-variation,Ensembl/ensembl-variation,willmclaren/ensembl-variation,willmclaren/ensembl-variation,Ensembl/ensembl-variation,willmclaren/ensembl-variation,willmclaren/ensembl-variation,Ensembl/ensembl-variation,Ensembl/ensembl-variation,Ensembl/ensembl-variation