Use best-fit strategy in Arena, now O(log(n)) instead O(n)#12048

Merged

laanwj merged 2 commits intobitcoin:masterfrom martinus:faster_arena

Mar 22, 2018

Commits on Dec 29, 2017

Use best-fit strategy in Arena, now O(log(n)) instead O(n)
martinus
committed

Commits on Jan 6, 2018

fix nits: variable naming, typos
martinus
committed