Get rid of all outdated "ClientIdentity" terminology.

This is instead of oidc.ClientIdentity. This makes it easier to add new
fields custom to dex to the client.

tests: add HandleTokenFunc test

Fixes #408

replace godep with glide

server: add more validation to --no-db static file parsing

db: print better error messages for invalid input

When client secrets are not base64 encoded, print an error message
that's not a generic base64 decode error:

   client secrets must be base64 decodable. See issue #337.
   Please consider replaceing "secret" with "c2VjcmV0"

When a user file is missing a mandatory field print an error message.

	Unable to build Server: user elroy-foo is missing email field

For #400

In #393 the format of the static user file in --no-db mode changed.
However, the old format loads without error, which has caused
issues for developers with existing user files.

Add an explicit check to ensure the file is not using the old
format. If they are, print a better error message.

It's part of the standard tooling and no longer lives in
golang.org/x/tools.

See https://golang.org/cl/20810

add ability to revoke refresh tokens in user API

remove passwordInfos from local connector

In --no-db mode, load passwords from the users file instead of the
connectors file. This allows us to remove the password infos field
from the local connector and stop loading them during connector
registration, a case that was causing panics when using a real
database (see #286).

Fixes #286
Closes #340

add client registration to the admin API

Documentation: remove reference to DEX_APP_REDIRECTURL

Fix response_type missing param

This commit fix problem with response_type param, which is required according to OIDC spec, when it is missing.
 At now, when connector_id url query param is not set, connector view use response_type that client request instead of default "code".

Fixes #370

*: remove build-units script

server: add db heatlh checker to server checkers

move outside dependencies to ./vendor directory

Documentation: update roadmap for 0.4 release cycle

closes #328