Removed jQuery dependency

Hi,

I have tried remove the jQuery dependency using standard api. I have introduced 'postVarName' to allow server side scripts retrieve data more simply  (i.e. PHP: $_POST['DBSYNC'] instead of reading input stream)
I also changed the mime type "application/j-son" to "application/json" according to [RFC4627](http://www.ietf.org/rfc/rfc4627.txt).

```
Tests completed in 1455 milliseconds.
20 tests of 20 passed, 0 failed.
```

Hoping this can be useful