Zoom enabled false fix and fix for allowing flexibility for new IPhotoView classes

**Fixes for two bugs I ran into:**
1) One prevented me from implementing my own PhotoView class (_as I could not extend PhotoView directly due to needing a pre-existing base class_).

2) When you set Zoomable to false, it was not properly scaling as FIT_CENTER. Instead it was just displaying actual size. No scaling. (_Identity base matrix_)