Starting To Add Tracking of Garden Crops/Guides to Gardens

# What's New
* started adding a user's garden page
![screenshot 2014-11-06 14 25 36](https://cloud.githubusercontent.com/assets/485583/4932212/48b4fb94-6586-11e4-8804-9bb06637244c.png)
* this goes alongside all the relevant angular services, garden controllers, garden crop controllers, and gardencrop mutations.
* guides can be added to gardens:
![screenshot 2014-11-06 14 26 12](https://cloud.githubusercontent.com/assets/485583/4932213/48bfa5f8-6586-11e4-8f45-684a81940e58.png)

# What's next
* Finish a lot of these things, this is mainly here for comment.

I also wanted to discuss - this might be something I missed in the designs: does the garden have crops or does it have guides? What if a user mixes and matches guides for several guides that they're using? @roryaronson @emily-plummer @warpling 

Identifier 'user_id' is not in camel case.