inline_caching, a fix for has_one, and automatic ancestor id params

Hey guys!

I'm switching from active-resource to her in my company. During this switch (isn't completed yet) I made some additions to the gem. I hope you like it and will integrate into the main gem.

Inline Caching:
We are going to integrate with an external cache system and looked for a way to better control caching inside of Her. With "disable_inline_caching" the inline caching functionality can be controlled on a per model basis.

Has One Fix:
This is a little fix to allow the has_one association to allow custom primary_keys on build.

Ancestors:
Since we are building complex internal API's with many levels of nesting. I created a way to better handling automatic id lookup's when building on a nested collection.

Shorthand .first
I added the shorthand .first to match active record's behavior.

Reload
The reload method on all instances allow data reloading from the api.

Parameter Wrapping
Our API only accepts parameters for filters in a wrapped object. To easily make this available i added the "wrap_parameters_for_requests" options to models.

Tell me what you think about these additions!