[OAuth2Provider] Added API and resource in front end to manage OAuth2 client apps

Review Request #7993 — Created Feb. 23, 2016 and discarded — Latest diff uploaded


Review Board


This patch add full API support to get lists of OAuth2 client app,
get, update or delete a single app instance or create a new one.
User can also operate those operation through the webUI at My account

Ran python ./tests/runtests.py reviewboard.webapi.tests.test_oauth2_client_app

Test DELETE, GET, PUT on single item
Test GET, POST on list endpoint