Make UseRemote work for dev_appserver too.

Make UseRemote work for dev_appserver too.

Now interacting with remote_api is as simple as:

    ```go
    ctx := context.Background()
    if err := prod.UseRemote(&ctx, "localhost:8080", nil); err != nil {
      panic(err)
    }
    // ctx is usable with luci/gae
    ```

Also changes the context-derivation function signature to be safer, since the
client's context will always be valid, and can be used for things, such as
logging even in the error handling case.

This also makes UseRemote work when used FROM appengine to another appengine
app.

Fixes #36.

R=dnj@chromium.org, estaab@chromium.org, martiniss@chromium.org, vadimsh@chromium.org
BUG=

Committed: https://github.com/luci/gae/commit/ed44bee34120a74ccb1a6b026752fd905b2517e1

[martiniss, 2016-01-05 18:13:57]

lgtm so far... but you said you would be adding tests, right? Not sure where
those go, but I'd like to see them :)

wait for other lgtms as well though

[iannucci, 2016-01-05 19:22:26]

On 2016/01/05 at 18:13:57, martiniss wrote:
> lgtm so far... but you said you would be adding tests, right? Not sure where
those go, but I'd like to see them :)
> 
> wait for other lgtms as well though

I tried to add tests, but it's super messy. Basically I have to generate a new
temporary appengine app, 'serve' it with goapp, wait for it to come up, then try
to create a remote api... and that only exercises the dev_appserver portion, I
have NO idea how to test the oauth bits :/

[iannucci, 2016-01-05 19:23:21]

Description was changed from

==========
Make UseRemote work for dev_appserver too.

Now interacting with remote_api is as simple as:

    ```go
    ctx := context.Background()
    if err := prod.UseRemote(&ctx, "localhost:8080", nil); err != nil {
      panic(err)
    }
    // ctx is usable with luci/gae
    ```

Also changes the context-derivation function signature to be safer, since the
client's context will always be valid, and can be used for things, such as
logging even in the error handling case.

R=dnj@chromium.org, estaab@chromium.org, martiniss@chromium.org,
vadimsh@chromium.org
BUG=
==========

to

==========
Make UseRemote work for dev_appserver too.

Now interacting with remote_api is as simple as:

    ```go
    ctx := context.Background()
    if err := prod.UseRemote(&ctx, "localhost:8080", nil); err != nil {
      panic(err)
    }
    // ctx is usable with luci/gae
    ```

Also changes the context-derivation function signature to be safer, since the
client's context will always be valid, and can be used for things, such as
logging even in the error handling case.

This also makes UseRemote work when used FROM appengine to another appengine
app.

Fixes #36.

R=dnj@chromium.org, estaab@chromium.org, martiniss@chromium.org,
vadimsh@chromium.org
BUG=
==========

[iannucci, 2016-01-05 19:24:13]

On 2016/01/05 at 19:22:26, iannucci wrote:
> On 2016/01/05 at 18:13:57, martiniss wrote:
> > lgtm so far... but you said you would be adding tests, right? Not sure where
those go, but I'd like to see them :)
> > 
> > wait for other lgtms as well though
> 
> I tried to add tests, but it's super messy. Basically I have to generate a new
temporary appengine app, 'serve' it with goapp, wait for it to come up, then try
to create a remote api... and that only exercises the dev_appserver portion, I
have NO idea how to test the oauth bits :/

Oh, and PTA(nother)L? I made it so that you can create a remote api FROM an
appengine app to another appengine app (I think :)).

[dnj, 2016-01-05 21:16:45]

lgtm

[iannucci, 2016-01-05 22:49:46]

The CQ bit was checked by iannucci@chromium.org

[iannucci, 2016-01-05 22:49:47]

The patchset sent to the CQ was uploaded after l-g-t-m from
martiniss@chromium.org
Link to the patchset: https://chromiumcodereview.appspot.com/1557223002/#ps20001
(title: "Add support for creating remote_api connections FROM appengine")

[commit-bot: I haz the power, 2016-01-05 22:49:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1557223002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1557223002/20001

[commit-bot: I haz the power, 2016-01-05 22:52:15]

Description was changed from

==========
Make UseRemote work for dev_appserver too.

Now interacting with remote_api is as simple as:

    ```go
    ctx := context.Background()
    if err := prod.UseRemote(&ctx, "localhost:8080", nil); err != nil {
      panic(err)
    }
    // ctx is usable with luci/gae
    ```

Also changes the context-derivation function signature to be safer, since the
client's context will always be valid, and can be used for things, such as
logging even in the error handling case.

This also makes UseRemote work when used FROM appengine to another appengine
app.

Fixes #36.

R=dnj@chromium.org, estaab@chromium.org, martiniss@chromium.org,
vadimsh@chromium.org
BUG=
==========

to

==========
Make UseRemote work for dev_appserver too.

Now interacting with remote_api is as simple as:

    ```go
    ctx := context.Background()
    if err := prod.UseRemote(&ctx, "localhost:8080", nil); err != nil {
      panic(err)
    }
    // ctx is usable with luci/gae
    ```

Also changes the context-derivation function signature to be safer, since the
client's context will always be valid, and can be used for things, such as
logging even in the error handling case.

This also makes UseRemote work when used FROM appengine to another appengine
app.

Fixes #36.

R=dnj@chromium.org, estaab@chromium.org, martiniss@chromium.org,
vadimsh@chromium.org
BUG=

Committed:
https://github.com/luci/gae/commit/ed44bee34120a74ccb1a6b026752fd905b2517e1
==========

[commit-bot: I haz the power, 2016-01-05 22:52:15]

Committed patchset #2 (id:20001) as
https://github.com/luci/gae/commit/ed44bee34120a74ccb1a6b026752fd905b2517e1