Features added/changed:

+ Completely rewrote volumetric lighting. Added crepuscular rays
+ Added cloud shadows
+ Added dynamic cloud weather system
+ Added a menu for changing the light color of light-emitting blocks
+ Added Aurora Borealis config menu
+ Added more tonemap options
+ Many more smaller changes which I won't write down here

Features fixed:

+ Fixed several compilation errors with Distant Horizons
+ Fixed light leaking on foliage in caves
+ Fixed lava cauldrons having incorrect lighting

Features removed:

+ Old volumetric lighting system