Installer-free Tomcat plugin

[Dain Sundstrom]

Ever since Dario pointed out that OpenJPA doesn't need a javaagent  
when on Java6, I've been wanting to try to get the Tomcat plugin  
working without the installer.  The two main tasks are getting  
OpenEJB to run on Java6 and finding a work around for the bad  
annotation-api.jar in Tomcat.  This morning it occurred to me that we  
can avoid the bad Tomcat PersistenceContext annotation using if we  
read the annotation data from the byte code directly using ASM. This  
completely bypasses the bad class.  I coded up this work around this  
afternoon, and it works like a charm.

So this leaves Java6, which I'm gonna work on next week.  With any  
luck, we can make the installer step a completely optional  
performance optimization.

-dain