Ability to perform SQL logging for Crowd

To help with troubleshooting cases, in some Atlassian products there are a feature to capture the SQL queries that are being executed when any action is done. This feature can be enabled through the Logging and Profiling screen. 

In Crowd however, there is no such feature in the Logging and Profiling screen and the only way to enable this by manually adding the following log parameters in the log4j.properties file

## Log hibernate prepared statements/SQL queries (equivalent to setting 'hibernate.show_sql' to 'true')
log4j.logger.org.hibernate.SQL=DEBUG
log4j.logger.org.hibernate.type=TRACE
log4j.appender.crowdlog.Threshold=TRACE 

The above approach means, 

• Crowd needs to be restarted for the properties to be activated.
• When the parameter needs to be removed, Crowd needs to be restarted again.