add WebRTC-Chat (a few bugs are still there, will be fixed in the future)
solve an error where Modules was used too early by moving the etherpad code in a function
change the minimal linesize from 4px to 1px and delete the maximal linesize of 30px
if an object gets too small by resizing (cannot be moved anymore), set the minimal width and height to 20px
improvement for the last commit (check for too small values while resizing, not after)
Find a new solution to prevent the use of Webarena with Internet Explorer
Fixed an error with missing image previews
Fixed an error with missing image previews (using the temp folder of the operating system)
Fit the height of the discussion object to the bounding box height
Small fix for the Discussion-Object
Change the intersection method of the ellipse object to be more precise (from bounding box to the real ellipse)
Change the intersection method of the polygon object 1: to be more precise (from bounding box to the real polygon) 2: now supporting even more or less than 6 edges
Change the intersection method of the line object to be more precise (from bounding box to the real line)
Change the intersection method of the image/file object to be more precise (from bounding box to the real pixels of the image)
Merge branch 'develop' into feature/ResponsivePositioning

* develop:
  Change the intersection method of the image/file object to be more precise (from bounding box to the real pixels of the image)
  Change the intersection method of the line object to be more precise (from bounding box to the real line)
  Change the intersection method of the polygon object 1: to be more precise (from bounding box to the real polygon) 2: now supporting even more or less than 6 edges
  Change the intersection method of the ellipse object to be more precise (from bounding box to the real ellipse)
  Small fix for the Discussion-Object
  Fit the height of the discussion object to the bounding box height
  Fixed an error with missing image previews (using the temp folder of the operating system)
  Fixed an error with missing image previews
  Find a new solution to prevent the use of Webarena with Internet Explorer
  improvement for the last commit (check for too small values while resizing, not after)
  if an object gets too small by resizing (cannot be moved anymore), set the minimal width and height to 20px
  change the minimal linesize from 4px to 1px and delete the maximal linesize of 30px
  solve an error where Modules was used too early by moving the etherpad code in a function
  add WebRTC-Chat (a few bugs are still there, will be fixed in the future)

Conflicts:
	source/config.default.js