Encourage the practice of using the Drupal issue node id as patch array key.
Merge pull request #211 from grayside/make-patch-example

Encourage the practice of using the Drupal issue node id as patch array key
Add an outline of a new 'drush' engine for update_info.
update_info drush engine: get releases info and manage caches.
update_info drush engine: discard caches if ctime of project is newer than cache.
update_info drush engine: remove download cache of update files.
Refactoring of release_info's updatexml engine.
Set 'drush' as default update_info engine.
Fix releaseInfo tests.
Fix reference to renamed function.
Fix wrong method name.
Better check for drupal bootstrap status. Fix Unish\pmDownloadCase::testSelect
Refactor pm_parse_project_version() to transform it into pm_parse_request() and pm_parse_version().
Move some logic based on the bootstrapped site out of release_info engine. This way, the info from the update service is cacheable in drush.
Add a special case to pm_parse_request() to manage Drupal core version. Also add tests for every variant of core version.