Merge branch 'workshop'
Update last version
Set _imp->zoomOrPannedSinceLastFit = true; when using combobox too
Roto: allow dragging points within the bounding box even if mouse is
not hovering the crosshair in the middle
Roto: you can now move a bezier shape just by dragging the curve from
in-between control points
Settings: auto-preview is back on by default
Roth: make sure we prefer selecting borders of selected points bbox
instead of the drag handle
Several changes:

- You can now choose the font and the font size for the application (a
restart of Natron is required for the change to be effective).

- The new default font is Muli from google

- A new progress bar indicates the progression while loading a project

- Changed the application’s icon & splash screen provided by JC Levet

- When zooming out of the node-graph, name of nodes and arrows will
disappear, improving performances of the node graph when panning
Remove assert: system fonts are not loaded in background mode
Roto: holding shift while dragging a the scale  handle of one of the
sides of the bounding box will scale only the half of the shape on the
side of the handle
Viewer channels choice: color the border of the drop-down to reflect
the current choice.

+ Update changeling
Fixed a bug introduced in RC3 when saving bezier curves control points.
We now restore compatibility with projects created prior to RC3 and
also fix a bug for all projects created during RC3.
Add project file icons
Add .ntp icon on OS X
Timeline: when repeating the left and right arrow keys, loop in the
frame range instead of crossing the bounds
Update changelog
Small fix for projects created prior to RC3
Fixed a bug where arrow labels would show up randomly on node graph
Set slider font to size 8
Remove assert which is not true
Update openfx