v2.4.0

• General changes
  • Documentation updates. (@rdvincent, @natacha-beck)
• Surface Viewer
  • Add lateral-medial view for non-split model. (@rdvincent)
  • Fix map overlay. (@natacha-beck)
  • ResetView now reset opacity too. (@natacha-beck)
  • Add drawGrid, drawLine and drawAxes. (@natacha-beck based on @lblewis work)
• Volume Viewer
  • Loader for NIfTI-1. (@rdvincent)
  • Improve overlay. (@rdvincent)
  • File reader for Freesurfer (MGH) volumetric data. (@rdvincent)