What's Changed
* Add a fixed handler for the base scene viewer widget. by hsorby in https://github.com/cmlibs-python/cmlibs.widgets/pull/79
* Fix ZoomOnly handler for base scene viewer widget. by hsorby in https://github.com/cmlibs-python/cmlibs.widgets/pull/80
* Update constrained node editor to make use of the adjaent element API. by hsorby in https://github.com/cmlibs-python/cmlibs.widgets/pull/81
**Full Changelog**: https://github.com/cmlibs-python/cmlibs.widgets/compare/v0.6.3...v0.6.4