Correct authentication and token generation v3 api

1. Remove a wrong route mapper for '/v3/tokens' path.
2. Correct NOAUTH list to include path of authentication and token
generation v3 api.
3. Correct authentication implementation of the api.
Adding pre-stage log on api request

Currently jumpgate only logs api response with a post-stage logging
handler, it's a limitation for real-time debugging if the handling of
api request was blocked or needs a while to process, operator or
developer needs to know what api is hanlding there now and which api
request the log belongs to that the main handling logic logged, so this
change added a pre-stage logging for api request.
Adding token validation api for v3 identity api

This change impleneted token valication api which is a major function as
a part of v3 identity api, some upper layer components used this
interface to validate v3 token.

An action handling function has been added which is used to handle the
http request received on /v3/auth/tokens endpoint with GET method.

Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Merge pull request #152 from LiuZhiyan/correct-v3-auth-token-gen-api

Correct authentication and token generation v3 api
Merge pull request #154 from LiuZhiyan/adding-pre-log-on-request

Adding pre-stage log on api request
Merge pull request #155 from LiuZhiyan/adding-v3-token-valication

Adding token validation api for v3 identity api
Correct region name of service catalog for identity V2 API

Currently the code of service catalog construction has a defect which
caused operator configured region name could not be able to apply into
the response of service catalog in such identity V2 APIs, and
"RegionOne" were used in any case [0] instead.

[0]
https://github.com/softlayer/jumpgate/blob/master/jumpgate/identity/drivers/sl/tokens.py#L210

Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Merge pull request #157 from LiuZhiyan/correct-v2-service-catalog-region-name

Correct region name of service catalog for identity V2 API
Merge pull request #3 from softlayer/master

Roll-up