This introduces a breaking change.
This options replaces the various `constrainResolution` options on interactions
and the `fit` method.
Since constraints are now the responsibility of the View, the fact that intermediary
zoom levels are allowed or not is now set in the view options.
By default, the view resolution is unconstrained.
Fit accepts either a geometry or an extent.
This combines two previously distinct functions
into one more flexible call.
Also brings the rotations support and options
previously available to fitGeometry to extents
Andreas Hocevar
Olivier Guyot
Tim Schaub
vmalaret
Frederic Junod
Antoine Abt
Stéphane Brunner