Feature request: log to stderr logger + LOG file

[zaidoon1]

background:
currently logs can either be written to a LOG file or they can be diverted to stderr logger for example. In my case, I don't have access to the machines that run rocksdb and need to ask someone else with access to pull the LOG files. To workaround that, i've started using the stderr logger to see issues but to avoid overloading the logging pipeline, i'm only logging WARN level logs.

Ask:
What I would like to do is have info level logs go to LOG file so that I can get more info on how rocksdb is performing when needed while at the same time having WARN level logs go to stderr logger that I have immediate access to