Fix event unsubscribe for image viewer
Fix ambiguity between HIPS dataType property & VectorLayer's one
  * Rename HEALPixFitsLayer "dataType" property to "format"
Do not pollute global space
Fix upload progress bar issue on Firefox
Fix canvas resizing on window resize
Add possibility to choose color on highlight, fix explorer example
  * Highlight color is red for now
  * Speed up zoom to
  * Change canvas size to fit into smaller screens
Split reverse name resolver on model & view
  * TODO: still have to define the reverse name resolver protocol in planet context
Tiny cleanup