Agent

I've removed the -baseaspect option in javamopagent, and only keep that option in javamop.
I've inlined the contents of the default BaseAspect.aj in the .aj file generated by javamop if there is no user defined BaseAspect is provided.
I also modify the name of the aspect generated by javamop in -merge option so that it is consistent with the library generated by rv-monitor.

I've passed the mvn verify, and maybe @seriousamlqz we  can discuss how to compare the contents of agent.jar generated by previous javamop's -agent option and the one generated by our separate javamopagent tool in order to increase our confidence.