Description
-----------

     The Logger class provides a simple but sophisticated logging
     utility that anyone can use because it's included in the Ruby 1.8.x
     standard library.

     The HOWTOs below give a code-based overview of Logger's usage, but
     the basic concept is as follows. You create a Logger object (output
     to a file or elsewhere), and use it to log messages. The messages
     will have varying levels (+info+, +error+, etc), reflecting their
     varying importance. The levels, and their meanings, are:

     +FATAL+: an unhandleable error that results in a program crash

     +ERROR+: a handleable error condition

     +WARN+:  a warning

     +INFO+:  generic (useful) information about system operation

     +DEBUG+: low-level information for developers

     So each message has a level, and the Logger itself has a level,
     which acts as a filter, so you can control the amount of
     information emitted from the logger without having to remove actual
     messages.

     For instance, in a production system, you may have your logger(s)
     set to +INFO+ (or +WARN+ if you don't want the log files growing
     large with repetitive information). When you are developing it,
     though, you probably want to know about the program's internal
     state, and would set them to +DEBUG+.