Update pm-dl and friends with the new XML update format

[damz]

Drush currently identifies the type of project (module, theme, distribution, etc.) using a vocabulary term that we used to use on Drupal.org when on Drupal 6. Something like this:

<term>
  <name>Projects</name>
  <value>Drupal core</value>
</term>

This was never meant to be used this way. It is very brittle (because it relies on the name of a taxonomy term, that is not a primary key). We broke it a few times in the past.

On Drupal 7, we now have different project types (node types) for the different project types. We added a <type> key in the XML:

<type>project_core</type>

The possible values for this key are:

  project_core
  project_distribution
  project_module
  project_theme
  project_theme_engine
  project_translation

They are guaranteed to be stable, even if we reserve the right to add new values in the future.

We are not using vocabulary anymore for this. So the old keys were missing from the XML when the Drupal 7 version went live. Yesterday, we deployed a compatibility fix that adds back the old keys.

Drush needs to be updated (all supported branches, ideally) to use this new format, as we would like to deprecate the old format as soon as possible.

[weitzman]

Backported to 6.x and 5.x. I expect to release 6.2.0 this weekend.

[damz]

Thanks @weitzman! 👍