Allow to customize log_name for services

This patch allows us to customize log_name for:
- proxy-server
- container-server
- object-server
- account-server

Which may be usefull for log collecting/parsing. Defaults remain
as they were before the patch.

Change-Id: I173652ec5bbe8d4382e10db4510d91aebceacab5
Merge "Allow to customize log_name for services"