- removed previoulsy deprecated getFirstFilter() method in
  FilterAttachable interface

- preparing release 0.9.20

- started to add if/then/else support in Joran
- removed duplicate logback-examples/src/main/java/chapters/appenders/onJoran/ folder

- tests pass for PostgreSQL, Oracle 10, MySQL, H2, HSQL

fixing http://jira.qos.ch/browse/LBCLASSIC-198 (more tests to follow)

code compiles but the test do NOT pass. To be considered as ongoing work.

a case insensitive way as specified in RFC 2616.  This prevents
compatibility issues, in particular with recent versions of Tomcat
whcih store request header names in lower-case.

found in DBAppenderTestFixture.java in the ch.qos.logback.access.db
and ch.qos.logback.classic.db packages under src/test.

automatically defined and added to the logger context.  This value
comes in handy in a variety of situations.

- fixed http://jira.qos.ch/browse/LBSITE-35

working with development done on Linux where the line endings is LF.
This is still somewhat experimental.

 SDOAware interface has been removed.
 ILoggerEvent interface no longer extends SDOAware.
 
 Appenders which rely on serialization invoke the appropriate PreSerializationTransformer
 to obtain a serializable representation of the event they are processing. 

This fairly extensive commit in terms of the number of affected
classes but relatively small conceptually. It is a refactoring of the
LoggingEvent class. The LoggingEvent class now implements the
ILoggingEvent interface which essentially contains getter methods with
no setters.  LoggingEvent is no longer serializable because the
relavant serialization code has been moved into LoggingEventSDO. A
LoggingEvent object now requires transformation into LoggingEventSDO
object before serializaiton. LoggingEventSDO class implements the
ILoggingEvent interface. SDO stands for Serialable Data Object.

All logback-classic components, including appenders, layouts,
converters now operate on ILoggingEvent instances. In other words,
logback-classic module is now a specialized processing chain for
ILoggingEvent objects, instead of LoggerEvent objects previously.

The getStartTime method which was previously part of LoggingEvent has
migrated to the Context interface. This change is a nice fit from a
conceptual point of view.

All tests pass. Performance is has not been degraded. 

In the future commits, the LoggerRemoteView may be renamed as
LoggerSDO, and similarly, LoggerContextRemoteView as LoggerContextSDO.

- to method to remove files is called "unlink" in perl

Also added an FAQ entry about logback dependencies

This fixes LBGENERAL-8

  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

Related to LBCORE-83.