Remove thirdparty/pbkdf2

Remove thirdparty/pbkdf2

In preparation for the migration to github remove the private copy of pbkdf2.

It is probable that when this package was added, somewhere around 18 months ago, we did not have godeps or a established way of managing dependencies, so vendoring the package made sense at the time.

The only differences between our privat copy and the upstream is our inclusion of our note that the package is a fork.

ubuntu@winton-02:~$ diff -u ~/src/launchpad.net/juju-core/thirdparty/pbkdf2/pbkdf2.go  /home/ubuntu/src/code.google.com/p/go.crypto/pbkdf2/pbkdf2.go
--- /home/ubuntu/src/launchpad.net/juju-core/thirdparty/pbkdf2/pbkdf2.go        2014-05-21 00:46:49.130817000 +0000
+++ /home/ubuntu/src/code.google.com/p/go.crypto/pbkdf2/pbkdf2.go       2014-05-21 00:46:54.275885894 +0000
@@ -1,5 +1,3 @@
-// Original package at code.google.com/p/go.crypto/pbkdf2
-
 // Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
ubuntu@winton-02:~$ diff -u ~/src/launchpad.net/juju-core/thirdparty/pbkdf2/pbkdf2_test.go  /home/ubuntu/src/code.google.com/p/go.crypto/pbkdf2/pbkdf2_test.go

https://code.launchpad.net/~dave-cheney/juju-core/179-remove-thirdparty-pbkdf2-dependency/+merge/220341

Requires: https://code.launchpad.net/~dave-cheney/juju-core/178-update-errgo-and-loggo-dependencies/+merge/220340

(do not edit description out of merge proposal)

[dave_cheney.net, 2014-05-21 01:33:16]

Please take a look.

[axw, 2014-05-21 01:39:39]

On 2014/05/21 01:33:16, dfc wrote:
> Please take a look.

LGTM

[dave_cheney.net, 2014-05-21 02:36:19]

Please take a look.