v2.4

Changes

• #55 UnzipTask (archive_unzip): new max_files and max_size options (default null, no limit) to protect the server against "zip bombs": the number of entries and their total uncompressed size are checked before anything is extracted, the task fails with a RuntimeException when a limit is exceeded. Update documentation, add tests.
• #62 Cookbook: task codes instead of the deprecated service:, broken link; exceptions of the bundle in the reference pages.