Change docs color theme for 0.8
New hardware provisioning doc, and updates to menus
More doc improvements + better warnings when you haven't built Spark
Update docs about HDFS versions
More updates, describing changes to recommended use of environment vars
and new Python stuff
Fixes suggested by Patrick
Another fix suggested by Patrick
Merge pull request #877 from mateiz/docs

Doc improvements for 0.8
Small fixes to README