* move all push update to git hook post-receive and protected branch check to git hook pre-receive

* add SSH_ORIGINAL_COMMAND check back

* remove all unused codes

* fix the import

* initial stuff for oauth2 login, fails on:
* login button on the signIn page to start the OAuth2 flow and a callback for each provider
Only GitHub is implemented for now
* show login button only when the OAuth2 consumer is configured (and activated)
* create macaron group for oauth2 urls
* prevent net/http in modules (other then oauth2)
* use a new data sessions oauth2 folder for storing the oauth2 session data
* add missing 2FA when this is enabled on the user
* add password option for OAuth2 user , for use with git over http and login to the GUI
* add tip for registering a GitHub OAuth application
* at startup of Gitea register all configured providers and also on adding/deleting of new providers
* custom handling of errors in oauth2 request init + show better tip
* add ExternalLoginUser model and migration script to add it to database
* link a external account to an existing account (still need to handle wrong login and signup) and remove if user is removed
* remove the linked external account from the user his settings
* if user is unknown we allow him to register a new account or link it to some existing account
* sign up with button on signin page (als change OAuth2Provider structure so we can store basic stuff about providers)

* from gorilla/sessions docs:
"Important Note: If you aren't using gorilla/mux, you need to wrap your handlers with context.ClearHandler as or else you will leak memory!"
(we're using gorilla/sessions for storing oauth2 sessions)

* use updated goth lib that now supports getting the OAuth2 user if the AccessToken is still valid instead of re-authenticating (prevent flooding the OAuth2 provider)

* Protected branches system

* Moved default branch to branches section (`:org/:reponame/settings/branches`).
* Initial support Protected Branch.
  - Admin does not restrict
  - Owner not to limit
  - To write permission restrictions

* reformat tmpl

* finished the UI and add/delete protected branch response

* remove unused comment

* indent all the template files and remove ru translations since we use crowdin

* fix the push bug

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

- Update import paths from github.com/go-gitea to code.gitea.io
- Fix import path for travis

See https://docs.travis-ci.com/user/languages/go#Go-Import-Path

Disable HTTP cloning

* Replace gogits/git-module dependency with go-gitea/git

Fixes #92

* Remove git alias for git module import (not needed)

Remove the possibility of using email as user name when user actually push
through combination of email and password with HTTP.

Also refactor update action function to replcae tons of arguments with
single PushUpdateOptions struct.
And define the user who pushes code as pusher, therefore variable names shouldn't
be confusing any more.

This is because git command line shows the failure reason only if Content-Type is text/plain.

Conflicts:
	cmd/serve.go
	models/access.go
	models/migrations/migrations.go
	models/org.go
	models/repo.go
	models/user.go
	modules/middleware/org.go
	modules/middleware/repo.go
	routers/api/v1/repo.go
	routers/org/teams.go
	routers/repo/http.go
	routers/user/home.go

This commit does a lot of the work of refactoring the access table in a table with id's instead of strings.

The result does compile, but has not been tested. It may eat your kittens.