API Revamp

This is a pull request to make the proposal API better.

This pull request:

  * Causes the basic information about a proposal to be pulled down when proposal data is requested, as well as API-written data.
  * Replaces the  API keys in the URLs. This isn't bank data, but it's just private enough that API keys in open URLs as a security mechanism is insufficient. API keys are now sent in headers, and requests must be signed with a secret key.