Checking in generic add sample landing page

Fixes issue #568

Adds a top level menu item to "Log Sample..."
This option is only available after the kit has been verified.
Lists all available sources to choose from and will take the user to the intended add sample page when clicked.

![screen shot 2014-01-07 at 7 53 32 pm](https://f.cloud.github.com/assets/930642/1865491/e5d7af48-7810-11e3-9b04-bb29564ebfe4.png)

I also updated the add_animal_sample page so that it lists the name of the clicked animal at the top as it does on the add human sample page.