Squashed 'Extern/VFLib/' changes from 0d58754..3181389

3181389 Refine angle/distance calculations
1360b7a Fix order of compositors
0732c8f Lift juce::Rectangle to avoid ambiguous symbol
b25abd8 Put blend modes into pixel procs
a0271c0 Fix colour transfer in image fill
0c790d34 Fix Xcode compile

git-subtree-dir: Extern/VFLib
git-subtree-split: 31813893973f0fce9867c98111d2f53048bd5701
Merge commit '151d0390a46ae73da1b600044b259ea05c5e9097'