making a pass over INSTALL.md

@seriousamlqz, @kheradmand, @xiaohe27, please review
the ajc script is something like this: 
`"$JAVA_HOME/bin/java" -classpath "$ASPECTJ_HOME/lib/aspectjtools.jar:$JAVA_HOME/lib/tools.jar:$CLASSPATH" -Xmx128M org.aspectj.tools.ajc.Main "$@"`
So, to weave the code, we also need to have "aspectjweaver.jar" on the classpath.