Created SofMask AVX vectorization implementation.
This is tested using the more extensive similarity test (now naively implemented with nested loops)
The code has been Profiled using XCode-Instruments. And it shows no bottle necks on the curveData retrieval code, which worried me in principle.
About: CurvedData. we retrieve the values from a pointer using the Vc::Vector.gather method, which takes the values from a data pointer using an index as the positions to retrieve.
BenchMark shows a scalar/vectorized values around 25.3/4.3, while the gain might not be as impressive as DEfault brush, the "real world" usage shown by FreeStrokeBenchMark, shows it is fast. Compared with the Default implementation we have: Default/Vector = 5100/6800
This patch is the diferential of my branch and master.