and log4j appenders to logback as requested in LBSITE-27

field called layout.  This is related to LBCORE-56 

See also http://qos.ch/pipermail/logback-dev/2009-February/003660.html

This is an initial implementation based on my previous work on log4j.

  in relation to  LBSITE-25 and LBSITE-24.
- Cosmetic changes in code.

See also http://java.sun.com/javase/6/docs/api/java/util/concurrent/locks/Lock.html

This issue was discussed on the logback-dev list in Feb 2009 under the subject 
"IllegalMonitorStateException inAppenderAttachableImpl.appendLoopOnAppenders()"

  logback-access uses it as well.
  
- Added unit tests in relation with default component class mapping rules in Joran. 
  See also jira issue LBCLASSIC-103

Joran is now able to assume a default type for nested components according
to rules declared in a JoranConfigurator instance. The rules are located in
an instance of the DefaultNestedComponentRegistry class. 

Thus, in many cases it will no longer be necessary to declare the class of a
component in configuration files.

Since the logback-classic and logback-access modes have their own JoranConfigurator
classes, it is now possible to register rules specific to each logback module.
For example, there is now a rule which maps the layout of an appender to a 
c.q.l.classic.PatternLayout instance for all appenders in  logback-classic and to
and instance of c.q.l.access.PatternLayout for all appenders in logback-access.

This is still ongoing and incomplete work.

as an attribute and not as a nested element. However, the code still honors the old covention.

Fixes LBCLASSIC-104.

The prepareForDeferredProcessing() method in LoggingEvent now  creates a copy mdcPropertiesMap. 
It follows that if the MDC is subsequently modified, the logging events are not impacted.

SMTPAppender in lb-classic now invokes event.prepareForDeferredProcessing() method in subAppend().

Added relevant test case.

Related to LBCORE-83.
 

- added blurb in the news about ViewStatusServlet

- Added StatusMessage viewer servlet for lb-classic called ViewStatusMessagesServlet. 

- Added StatusMessage viewer servlet for lb-access called ViewStatusMessagesServlet. 
  It works with Tomcat but not Jetty.

- Added relevant documentation.

- the section on logback initialization references the FAQ entry (location of config 
  files on the class path). This fixes LBSITE-20.
- minor enhancements in architecture.html relating to the basic selection rule
- updates to news.html

- LoggerContext reset, registered turbo filters are first stopped before being 
  unregistered. This fixes LBCLASSIC-89.
    

  automatically print status data on the console in case of warnings
  as well as errors. Previously, status data was printed only in
  case of errors.

- In case multiple configuration files are found on the class
  path, ContextInitializer will now emit a warning. This fixes 
  LBCLASSIC-85.

Documentation enhancements. Closing LBCLASSIC-30

ContextInitializer now prints the url it uses for default configuration.
This was requested in LBCLASSIC-55.