embedded java for attribute blocks

CHANGELOG.md

src/main/grammar/Aspect.bnf

...java/org/jastadd/tooling/aspect/JavaLanguageInjector.java

...d/tooling/aspect/psi/JastAddAspectJavaBlockExtension.java

...astadd/tooling/aspect/psi/JastAddAspectJavaExtension.java

...oling/aspect/psi/impl/JastAddAspectJavaImplExtension.java

src/main/resources/META-INF/plugin.xml