saving with params and default params

[Esad Hajdarevic]

Hi,

I just tried out the newest version of jester from git and discovered
that there's a small bug when saving: even if you pass no params to
save(), the values a resource has (like id, name) are appended to the
URL resulting in POST queries like this:

POST http://localhost:3000/items.json?label_id=12&text=Testing&id

instead of

POST http://localhost:3000/items.json (the params should be in the
body of post request)

I've made a fork at http://github.com/esad/jester/tree/master where I
fixed this behaviour. I also added some more tests that should cover
this.

The only thing I was unsure about are defaultParams: right now they
are 'interpolated' into URL, but I think it only makes sense for
"find", "show" and "destroy" actions; whereas create/update should, as
noted above, put these into request body.

Could you please take a look at the changes and possibly marge this
into master

Thanks for the great work,

Esad