Adds bug spec
Implements bulk file attachment on AaA
Attaches files before saving the work package
Prevents saving a new WP on attachment change
Fixes spec
Adds changelog entry
Adds specs for update action
Adapts update's to create's attachment behavior
Adapts spec to changed update behavior
Merge remote-tracking branch 'origin/feature/rails3' into bug/no_journal_entry_for_attachments_on_creation

Conflicts:
	doc/CHANGELOG.md
Reintroduce container validation
Use after validation hook to yield attachment errors to work packages
Merge pull request #512 from opf/bug/no_journal_entry_for_attachments_on_creation

[BUG] No journal entry for attachments on creation