Merge branch 'fmt10' into 'master'

Update to fmt10

In order to reduce warnings, I propose an update to fmt10.

It builds over the other MR

* fmt10 needs a small change in Hermes (branch fmt10)
* fmt10 needs changes in date library 
* It produces segfaults as we get stuck in a syscall loop
* Removed date library and replaced with a small gmtime replacement without timezone
* Rocksdb updated
* 
* 0.9.3 docker images created

See merge request !172