Update package-release-nodes.php to D7 in Drush

This issue also covers any updates to the project_release_node_rebuild_metadata table. Information from that is shown on release node view, but this script is in charge of populating and using values. It may be replaced with a field.

#381956: Mark project releases as "to be updated" only if pushes happen there is also related. Currently, I'm focusing on making a drush command work for manually packaging a single project. When that is good, we'll want to use D7 core's queue for automated packaging.

I pushed a few commits for this. Notable changes are

• This is now drush.
• Project's custom logging has been replaced with either drush functions or watchdog. During packaging, an implementation of hook_watchdog records packaging error messages to the project_release_package_errors table.
• Project's custom temporary directory handling and shell execution have been replaced with drush functions.

The main work left is

• Record files generated in the new release node's field structure. project_release_packager_update_node() has the commented-out code.
• Add a drush command for package queue running.

Drupalorg followup: #1824414: Update release_packager plugins for D7

I committed some more code for this and basic packaging a release is working. Leaving open for re-packaging.

another tag

The prerequisites for this issue, and packaging queuing is now done. #1878418: Queue release packaging at git code arrival is a followup.