SLF4J , Simple Logging Facade for Java#

website JIRA issue 376

Steps#

1. run the slf4j migrator
2. add the slf4j-api.jar to the eclipse buildpath
3. add the slf4j-simple-1.5.3.jar in tests/lib
4. src change: log.fatal( ==> log.error(
5. src change: slf4j log methods only accept Strings, so log.error(Exception) ==> log.error(Exception.toString())
6. PropertyConfigurator.configure(props) all over the place (mostly in tests) ==> move log4j properties from jspwiki.properties to separate log4j.properties (in classpath) ?
7. NDC => MDC ?, these are only in the two ServletFilters, if we still need them, what will we use as key (cookie ?)
8. change build.xml so that slf4j-api.jar is added to WEB-INF/lib
9. run the tests and the web-tests
10. test with tomcat
11. test with WebSphere (old JSPWiki version and new (slf4j) JSPWiki version