[major] API refactoring to add investigator lookup/creation endpoints and search
[medium] keyring-less public key management in api

t'sall in databases now!
[minor] fix keyring io.Reader copy in api
[minor] merge pgp/sign and pgp/verify packages into main pgp
[major] refactor scheduler PGP keyring management

Similar to the work done on the api, instead of managing investigator's keys
with a gpg keyring on disk, pull the keys from the database and manage a
keyring in memory.
The addition here is the management of the scheduler's own investigator
identity, that's used during the upgrade protocol to kill old agents. That private
key is also stored in the database, with permissions that limit the access to the
column to the schedulers themselves.
[minor] split up api pgp code into separate file
[minor] fix pgp/sign call in action_launcher
[minor/bug] perform http status code check before unmarshalling in console
[minor] move agent reader file around
[medium] investigator reader in console
[minor] add creation/modification timestamp to investigator.
[minor] fix api search queries
[doc] database doc update
[medium] create investigator from console

This includes some PGP work to retrieve a public key from a keyserver, and post
all of that to the API.
[medium] investigator status update in console, api and database (with doc)
[minor] various nits (error checks, http codes, ...)
[doc] display html list buttons
Merge pull request #26 from mozilla/keydelivery

[major] Investigators & keys management