Groovy AOP - Redesigned #2

OK, I'm now continuing to show that what've I made changes to the syntax of Groovy AOP.
Last post, I've showed the new syntax, and there's a few more tweaks here.

In the trunk, now we can have aspect like this:

class MyClass {
static aspect = {
before(call:'update1') { println 'before update 1 ..'}
after(call:'update2') { println 'after update 2 ..' }
}
}

and this:

class MyClass {
static aspect = {
before('update1') { println 'before update 1 ..'}
after('update2') { println 'after update 2 ..' }
}
}

Both have the same semantic. They read, before the call of (join point of) MyClass#update1, do ..., and after the call of (join point of) MyClass#update2 do ...
I think these shortcuts will be comfortable enough for people to use without AOP knowledge.

The implementation's also changed internally to override MetaClassImpl#invokeMissingMethod rather than MetaClassImpl#invokeMethod.