Improved JMX handling on ActiveMQ broker for tests

Disabled jmx for tests that don't need to use it and also add
AvailablePortFinder to dinamically assing JMX connector port when
needed.
Merge branch 'camel-jmx' of https://github.com/cristianonicolai/camel

Conflicts:
	components/camel-sjms/src/test/java/org/apache/camel/component/sjms/jms/SessionPoolTest.java
	components/camel-sjms/src/test/java/org/apache/camel/component/sjms/support/JmsTestSupport.java