add reopen to Logger::Base
Add Log.reopen that just delegates to @logger.reopen
maint - add basic file_logger_spec.rb

Here we add some basic testing to File_logger.   There's not much
to test, as most of File_logger simply delegates to ::Logger.
reopen implementation for the FileLogger

we need to make note of the current loglevel, as it may not be the version from
the config file that start will assert
MCO-328 hook SIGWINCH to Log.reopen

USR1 and USR2 are already taken, so we're left with SIGWINCH.  SIGWINCH is sent
when the terminal driver detects that the terminal has changed size, and is
most applicable to full-screen console applications.