small adjustments to make things work

  - EmailProvider now uses sets rather than lists/dictionaries
    - nodes list avoid awkward =True stuff
    - edges list now 30% of original size
  - set default edge value to be 0.9 so is possible to reach with [min, max) bounded connectivity slider
  - Uses Sharon's Github User's emoticon thing as page's icon
  - give dataProvider non-null minThreshold, which unfortunately must be provided.