Display user's pending requests in manage profile

- Implement User#pending_contributor_requests, which returns all of the pending
  contributor requests for a user.
Display requests to join an organization

- Create OrganizationAuthorizer#manage_requests_to_join
- Add missing # in OrganizationAuthorizer.
- Create requests_to_join action for Organizations
- Constrain requests to join route to env enablement
- Implement Organization#pending_requests_to_join
- CclaSignaturesHelper#organization_tab supports rel
- Add Requests to Join to ccla sig/org tab nav
- Constrain Requests to Join tab to env enablement
Add manage cookbook dropdown

The buttons in the cookbooks sidebar are getting out of hand so this
moves the functionality into a common manage cookbook dropdown.
Merge pull request #630 from opscode/display_pending_requests

Display pending requests
Merge pull request #643 from opscode/cookbook-dropdown

Add manage cookbook dropdown
Update select2 styles

Add vendor select2 styles that make select2 look more consistent with
Foundation's styles, which Supermarket users for its base styles.
Merge pull request #644 from opscode/select2-styles

Update select2 styles
Add copy about deprecation to the modal.
Create the deprecate_search internal end-point

Create a unique search end-point in order for Cookbook deprecation select2
search to only return eligible cookbooks for deprecation. A cookbook is elgible
for deletion if it is not deprecated and not the cookbook to be deprecated.

Notes:

- the code in the controller should be moved into an instance method on cookbook
- the deprecation parts of the CookbooksController could be broken out into
  their own controller to KISS
- the enforcement of not replacing a cookbook w/ an already deprecated cookbook
  should be enforced at the Cookbook#deprecate level as well
Handle deprecation failure at the controller level

This could be improved by:

- improving Cookbook#deprecate to use record.save! and rescue from the error
- displaying the actual error
Implement Cookbook#deprecate_search

Move the logic from the CookbooksController#deprecate_search into an instance
method on Cookbook.
Only allow deprecation if replacement selected