Own handle function

[Smip]

I added ability to use own handle function.

I use this feature for upload images to server.

   modules = {
      imageDrop: {
           handler: this.upload.bind(this)
      }
    };

  upload(file, callback){
    const fb = new FormData();
    fb.append('file', file, file.name);
    this.filesService.addFile(fb).subscribe(event => {
      callback(event['response']);
    });
  }

[ariefurtado]

Can u generate a rc with this ??? I really need it :D

[Smip]

@ariefurtado Sorry, what do you mean by rc?

[stargazing-dino]

@kensnyder Any reason this hasn't been merged? It'd really help me at the moment

[kensnyder]

@Nolence I'm closing this PR in favor of a slightly different one. See PR #22. Please review and let me know if it will work for you before I merge it.