fast integer compression in C using the StreamVByte codec

 StreamVByte is a new integer compression technique that applies SIMD
 instructions (vectorization) to Google's Group Varint approach. The net
 result is faster than other byte-oriented compression techniques.
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 It includes fast differential coding.
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 It assumes a recent Intel processor (e.g., haswell or better) or an ARM
 processor with NEON instructions (which is almost all of them).