BF: another fvtk 5 to 6 incompatibility
Merge pull request #510 from Garyfallidis/fix_vtk6_issue

BF: another fvtk 5 to 6 incompatibility
DOC: repositioned tracking quick start in examples_index
DOC: added proper reference link from tracking_quick_start to new tracking API
DOC: added contents and highlighted new example sections
Merge pull request #514 from Garyfallidis/website-update-20Dec2014

Website update