Introduces table for attachment list
Introduces asynchronous delete for attachments
Moves attachment destroy tests to specs
Fixes wiki page attachment destroy
Adds cuke for bug
Adds changelog entry

[skip ci]
Uses let! instead of before
Refactores function implementation
Merge remote-tracking branch 'origin/feature/rails3' into bug/attachment_delete_closes_work_package_edit

Conflicts:
	doc/CHANGELOG.md
Fixes security issues around :visited in IE10.
Updates deprecated method call.
Moves noscript into body.
Introduces HTML5 doctype.
Restores now-line in timelines.

Date.DAY somehow doesn't exist anymore.
Changelog.
quick fix for failing cukes with impermanent memberships
Merge remote-tracking branch 'origin/feature/rails3' into bug/attachment_delete_closes_work_package_edit

Conflicts:
	doc/CHANGELOG.md
Refactor watcher validation of a user's permission to watch
Move part of the filtering in watchable#watcher_recipients on SQL-side
Add delayed job's rails 3 upgrate migration