range: Fix is_wrap_around()
range: Fix is_wrap_around()

In Origin, dht.Range() with equal values is considered a full wrap
around. Make our range<> recognize this.

So we have:

 ]x; x] - wrap around, full ring
 [x; x[ - wrap around, full ring
 ]x; x[ - wrap around, excluding x
 [x; x] - not wrap around, only x included

asias/scylla,rluta/scylla,duarten/scylla,rluta/scylla,kjniemi/scylla,justintung/scylla,kangkot/scylla,justintung/scylla,bowlofstew/scylla,justintung/scylla,wildinto/scylla,scylladb/scylla,bowlofstew/scylla,rluta/scylla,avikivity/scylla,kjniemi/scylla,scylladb/scylla,gwicke/scylla,kjniemi/scylla,capturePointer/scylla,senseb/scylla,shaunstanislaus/scylla,duarten/scylla,acbellini/scylla,asias/scylla,scylladb/scylla,respu/scylla,guiquanz/scylla,tempbottle/scylla,gwicke/scylla,rentongzhang/scylla,kangkot/scylla,eklitzke/scylla,raphaelsc/scylla,glommer/scylla,rentongzhang/scylla,guiquanz/scylla,duarten/scylla,aruanruan/scylla,phonkee/scylla,asias/scylla,capturePointer/scylla,linearregression/scylla,victorbriz/scylla,tempbottle/scylla,wildinto/scylla,scylladb/scylla,kangkot/scylla,senseb/scylla,avikivity/scylla,acbellini/scylla,capturePointer/scylla,raphaelsc/scylla,dwdm/scylla,glommer/scylla,senseb/scylla,guiquanz/scylla,stamhe/scylla,stamhe/scylla,raphaelsc/scylla,wildinto/scylla,stamhe/scylla,respu/scylla,eklitzke/scylla,gwicke/scylla,phonkee/scylla,acbellini/scylla,victorbriz/scylla,linearregression/scylla,rentongzhang/scylla,shaunstanislaus/scylla,bowlofstew/scylla,aruanruan/scylla,avikivity/scylla,aruanruan/scylla,linearregression/scylla,dwdm/scylla,phonkee/scylla,eklitzke/scylla,respu/scylla,victorbriz/scylla,dwdm/scylla,glommer/scylla,tempbottle/scylla,shaunstanislaus/scylla