1. use our own log4j.properties file instead of having grails auto-generate one
2. modify web.xml template to use spring's log4config listener instead of grail's one
3. remove duplicate slf4j library
4. leave log4j DSL in Config.groovy to enable logging when developing and running "grails run-war"
5. log is written to /var/log/bigbluebutton/bbb-web.log
git-svn-id: http://bigbluebutton.googlecode.com/svn/trunk@3231 af16638f-c34d-0410-8cfa-b39d5352b314
