asm-aj.jar is a processed version of an asm jar with the package prefix org.aspectj added.
We add the prefix to avoid clashing with other versions of asm that may be on a users
classpath.

To pick up a new version of asm and use it in AspectJ, use the build.xml script.  It 
requires jarjar (which you will have to download).

---
22-Feb-06: asm-aj.jar is the packaged prefixed version of asm-2.2.1.jar