Remove custom stylesheet, fall back to default because qmi isn't compatible with Doxygen 1.8.7
Merge branch 'master' of https://github.com/numenta/nupic.core into 80-engine-api-doc
Merge pull request #100 from utensil/80-engine-api-doc

Remove custom stylesheet, fall back to default because qmi isn't compatible with Doxygen 1.8.7