- preparing release 0.9.20

  the MDC used in DBAppenderIntegrationTest is suffixed with a random int value
  to avoid collisions

- Merged from http://github.com/nurkiewicz/logback with following changes:

* removed CustomDBNameResolver as joran currently does not support
setters with two arguments

*  Omitted bogus modifications in FileAppenderResilienceTest and
IncludeActionTest

- fest-assert added as a common test dependency

- edits to manual/configuration.html

- additional test cases for conditional processing

  or <include> statement nested <if> statements or <if> nested within
  <include>

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

- minor edits

- doc edits

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

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

- document the timzezone option in %date
- minor edits