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
Added migration to rename existing IssueCustomfields
Merge pull request #512 from opf/bug/no_journal_entry_for_attachments_on_creation

[BUG] No journal entry for attachments on creation
Adds migration for invalid attachable journals

Invalid attachable journals are those without an initial attachable
entry.
Refactors attachable repair migration
Adds message attachment spec
Fixes inital message attachment journal issue
Repairs messages' initial attachment journal
Removes superfluous and wrong comment