Piped sub-events get triggered multiple times

When you trigger a subevent on an emitter that is being piped to another emitter, the events get triggered multiple times

````
var LucidJS = require('LucidJS')
 	, a = LucidJS.emitter()
 	, b = LucidJS.emitter()

 
 a.on('emitter.event', function(name){
 	console.log('A: ', name)
 })

 b.on('emitter.event', function(name){
 	console.log('B: ', name)
 })

 a.pipe(b)
 b.trigger('foo.bar.baz')
````

Output:
````
B:  foo.bar.baz
A:  foo.bar.baz
A:  foo.bar  <-- Emitter A triggers foo.bar because of the call to trigger('foo.bar.baz')
A:  foo      <--- Same with Foo
B:  foo.bar  <-- Emitter B now triggers it's subevent, which is piped again to A even though A has already emitted these events with it's own call to trigger
A:  foo.bar  <--- Emitter A triggers foo.bar again because Emitter B triggers `emitter.event` with foo.bar 
A:  foo      <--- And so on..
B:  foo
A:  foo
````