Issue title: Uncaught TypeError
 Issue body: Just followed the instructions and Im seeing, but I don't have a line 2766 (Love CoffeeScript)

stanford-simple-nlp/lib/StanfordSimpleNLP.coffee:2766: Uncaught TypeError: undefined is not a function

 Comments: 
 Comment 0: Hey @silentrob, can you give more hints? Just writing your code here will be great.

 Comment 1: I just copied/paste the demo from the readme.. Ill give you a complete gist. node v0.10.24, 
Mountain:stanfordnlp robellis$ java -version
java version "1.7.0_45"
Java(TM) SE Runtime Environment (build 1.7.0_45-b18)
Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode)

 Comment 2: https://gist.github.com/silentrob/9945896

 Comment 3: It happens with any option.

 Comment 4: Unfortunately, I couldn't meet the Uncaught TypeError.

But I updated to use `coffee-script 1.7.1` from 1.6.x and `StanfordNLP 3.3.1` from 3.3.0 and `stanford-simple-nlp` was bumped to version `0.2.1`.

You may see a more informed error now.

So, follow below steps.
1. Reinstall it by `npm i deanna46@example.com'
2. Download [StanfordNLP 3.3.1](http://www-nlp.stanford.edu/software/stanford-corenlp-full-2014-01-04.zip) instead of 3.3.0, unzip & copy & paste it to your `jar/` directory.
3. Test it again and let me know the result please.

Thanks.

 Comment 5: Awesome. I will try it again.

 Comment 6: This is the trace now.

/Users/robellis/projects/stanfordnlp/node_modules/stanford-simple-nlp/lib/StanfordSimpleNLP.coffee:80
        return callback(new Error('Load a pipeline first.'));
               ^
TypeError: undefined is not a function
  at StanfordSimpleNLP.process (/Users/robellis/projects/stanfordnlp/node_modules/stanford-simple-nlp/lib/StanfordSimpleNLP.coffee:69:12)
  at /Users/robellis/projects/stanfordnlp/server.js:8:21
  at /Users/robellis/projects/stanfordnlp/node_modules/stanford-simple-nlp/lib/StanfordSimpleNLP.coffee:54:18

 Comment 7: I should be using the process method the same was as your test. process("...", function(err, res){});

 Comment 8: Okay I got it. You can't just call pares you need to call tokenize, ssplit and pos first. Java was returning an error and I think it was getting though and unsetting the callback. 

 Comment 9: Oh, I see. now then I can reproduce the problem. I'll fix it properly, thanks @silentrob!

 Comment 10: modified unclear examples - 8fef978c5e581f46045ce52f19314fc0d0976cb0

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