how about higher quality hash algorithm?

Although hash algorithm is not the Bottleneck of bigcache, the [smhasher](https://github.com/rurban/smhasher)(the project of hash function quality and speed tests) show that FVNa has poor quality while other hash func has higher.

Should we evaluate the default hash func of bigcache again? After [the question and answer of hash](https://stackoverflow.com/questions/3665247/fastest-hash-for-non-cryptographic-uses), lots of new hash functions come out, such as xxhash, wyhash, menhash, which have higher quality.

Due to some hash functions use hardware instructions provided by the CPU to accelerate (AVX2, SSE), we can use different hash func in different Platform, such as:
1. FVNa default
2. xxhash in amd

By the way, why bigcache has no dependence? Should only no dependence PR can be approve?

Look forward to your reply!