HyperLevelDB replacement

[runaum]

First of all, i'm sorry for my primitive English. I think that you can extremely improve imposm3 cache via replacement HyperLevelDB to LMDB.

LMDB official: http://symas.com/mdb/
Benchmarks: http://symas.com/mdb/hyperdex/, http://symas.com/mdb/hyperdex2/
GO wrapper for LMDB: https://github.com/szferi/gomdb (it's ugly than levigo)

GO is not my favorite language, so it's difficult for me to check it & submit a pull request. I think that this replacement is a chance to speed up your FTL import.

Have a nice day.

[runaum]

I was wrong, no performance impromevents at all. Sorry for this bad idea.