Added first version of JMXMon

Very much inspired by DbMon.
switched to using MBeanServerConnection directly instead of JMXConnector
Re-ordered parameters to JMXMonSampler constructor to mirror GUI layout.
First version of JMXMon unit tests.
Fixed unit tests. Had to do some compromises to get them working (making JMXMonCollector.jmxMonSamplers protected even though I would have liked to keep it private, for example)
Merge branch 'master' of https://github.com/undera/jmeter-plugins
Removed debug code in JMXMonTest that was accidentally checked in (including a call to System.exit() - oops!)
Added Gui test for JMXMon
Merge branch 'master' of https://github.com/undera/jmeter-plugins
Merge branch 'master' of https://github.com/undera/jmeter-plugins
Merge branch 'master' of https://github.com/undera/jmeter-plugins
Merge branch 'master' of https://github.com/undera/jmeter-plugins
Merge branch 'master' of https://github.com/cyberw/jmeter-plugins
Fixed JMXMonitor unit tests and re-enabled.
Fixed some unit tests. Added "Key" attribute for querying complex jmx values.
Added JMXMon wiki page
Accidentally used a specific host name instead of localhost in example JMX URI.
Merge pull request #15 from cyberw/master

Fixed JMXMonitor unit tests, added Key for querying composite JMX values. Re-enabled in GUI.