Version 2.1 - JMX update mostly

This is a minor update of version 2 based on some user's input:

• added methods reset and two versions of sampleAndReset to SimonMXBean;
• you can now use [, ], and _ in Simon names;
• timestamps for 0 are formated as undef in toString methods.

Check downloads on the right side of the project page, we also updated Javadoc for a few JMX classes - see JavaDoc for v2.1.

Thank you for your support, downloads, feedback and feature request/bug reports. ;-)