Java11

[akwiatek]

@kohsuke

This PR tries to address issue #46 and adds support for Java11. This PR essentially upgrades asm from version 6.0 to version 7.2 .

I have checked the changes against both Java8 and Java11 and was able to successfully:

• compile the project (mvn clean package),
• start an application with the agent jar attached,
• attach the agent to a running application,
• list open files in the built-in HTTP server in both of the above scenarios.

I have gathered less invasive changes in the 1^st commit ( e9ac84a ) and moved it into PR #47 hoping they could be merged faster.

Due to lack of org.kohsuke.asm7 package I had to switch to the upstream version ( org.ow2.asm ) . I'm not sure why asm6 has been re-packaged in the first place TBH, but the detector appears to work just fine without that re-packaging.

Of course, once there is org.kohsuke.asm7 available switching to org.ow2.asm won't be necessary.

[jumarko]

Works nicely on JDK 11, thanks a lot for this!