BTrace Fix on the Mac

The last blog post showed a work around for getting BTrace to work on a Mac, however as explained it fails when trying to probe Grails. I've been working with the BTrace developers and now have a solution. It will likely be some time before the next release. So for those who don't want to build from source, I put a drop on drop.io of a build.

Side notes:
1) It appears that all the scripts and assumptions for Java do not take in account the Mac. Groovy, Grails and previously BTrace all have references to a tools.jar in a place which is not correct on a Mac.
2) drop.io is new to me... and it appears worth the look. I will likely use drop.io in the future. Mostly for presention code drops. I like github for source references, but sometimes it is just quick and easy to tar or zip up what you have and drop it.
3) There is an interesting situation with BTrace which can be frustrating if you are not aware of it. If you have a failed BTrace session... such as a connection refused on the BTrace side, then it is not possible to BTrace it again with a fixed version of BTrace. You have to restart the application to be probed.