Deprecate LogUtil and redirect it's messages to slf4j logger.
Replace framework calls from LogUtil to gwt-slf4j.
Switch ManagementConsole to gwt-slf4j.
Add custom logging handlers, using a global format string (like
java.util.Logging)

Notable changes:
* Add Logging module to ErraiCommon
* Add four handlers (extending gwt-builtin handlers)
* Add ErraiSimpleFormatter (based on the java.util SimpleFormatter)
* Add StingFormat utility (emulating String#format(String, Object...))
* Add class for configuring handler log levels at runtime
Prevent log handler log levels from being overwritten by superclass
constructors.
Change signature of getHandler method to avoid caller having to cast return value.
Modify JBossLauncher http port while copying xml file.

This removes the need to restart the server (noticeably reducing the
start-up time).