Thanks @zachasme @dannyrb @Maistho @diego0020 @medihack!

* Added new file point projector which will convert points between the image coordinate system and the patient coordinate system
* Added synchronizer mechanism which is used to implement a number of new features
* New Feature - stack image position synchronizer
* New feature - stack image index synchronizer
* New feature - wwwc synchronizer
* New feature pan zoom synchronizer
* New tool - reference lines
* Bug fix - stack prefetch may turn off sometimes when it shouldn't
* Added examples for the new tools
* Added example metadataprovider