Update to the ClientLogin URL

[Jeffrey Posnick]

We want to let the developer community know about a change to the
officially supported URL for YouTube API ClientLogin requests.
Previously, developers who wanted to obtain authentication credentials
via a username and password had to send their ClientLogin request to
https://www.google.com/youtube/accounts/ClientLogin. The new URL that
we encourage all developers to use is https://www.google.com/accounts/ClientLogin.
This new URL has been functional for a while, and is the same URL that
other Google APIs use for ClientLogin requests. Switching YouTube API
ClientLogin traffic to the standard URL ensures that developers across
all of Google’s APIs will see standard behavior when logging users in.

All of the details regarding this switch as well as best practices for
performing ClientLogin requests can be found in our YouTube API
documentation (http://code.google.com/apis/youtube/2.0/
developers_guide_protocol_clientlogin.html). There is one specific
change in behavior that is worth calling out: responses from the new
ClientLogin URL will not include the YouTube username of the
authenticated user, which the old URL’s responses did provide. We
encourage developers to take advantage of the username default when
constructing YouTube API request URLs, which always refers to the
currently logged in user.

We have no immediate plans to disable the old ClientLogin URL, but we
do encourage developers to update their code at their earliest
convenience to point to the new URL. We will post again with further
details if and when the legacy URL is turned off.

Cheers,
-Jeff Posnick, YouTube API Team