Only use fc_gene_name if there are missing neurons

* a small step on the way to making fc_sub_scoremat more generic
  with a view to moving it to nat.nblast where it could be used for any
  kind of neuron
Merge branch 'master' of github.com:jefferis/flycircuit

* 'master' of github.com:jefferis/flycircuit:
  Bump version and update DESCRIPTION
  Add nat.nblast dependency to Travis config
  Update to use functionality ported into nat.nblast
Deprecate pop3dfc, switching to npop3d

* removes .plotted3d environment
refactor plot3dfc using plot3d.character
Add example for plot3dfc

* includes specification of colour and using soma=TRUE
Merge branch 'feature/remove-pop3dfc'

* feature/remove-pop3dfc:
  Add example for plot3dfc
  refactor plot3dfc using plot3d.character
  Deprecate pop3dfc, switching to npop3d

* closes #11
Depend on nat >=1.5.7 and nat.nblast >=1.2

* for refactored plot3dfc and plot3d.hclust etc
Bump version to 1.5