Big Changes
- Support ~#![no_std]~
- Add striping, gathers, and scatters.
- Add vector merging
- Add vectorized endianness operations
- Add limited vector swizzling
- Add lockstep packed iterators

Features
- Add tons of docstrings
- Allow ~FnMut~ closures in ~simd_map~ and ~simd_reduce~
- Vectorize operations on last elements of an uneven collection
- Implement compound assignment operators for architectures without hardware SIMD
- Add large vectors for architectures without hardware SIMD

Bugfixes & Minor Improvements
- Add a changelog
- Fix a correctness issue when mapping over uneven collections
- Vectorize min/max for SSE4.1
- Vectorize ~Upcast~ for SSE4.1
- Implement ~Downcast~ polyfills on many more vector types
- Implement and test ~[saturating_]{hadd,hsub}~ on more vector types.
- Undeprecate ~halfs~ and ~interleave~