Re #2976 Allow `id` values to be generated from a function given attrs
pass along model and comparator to cloned collection. Fixes #3013
Merge pull request #3032 from akre54/clone-opts

Pass along model and comparator to cloned collection
Merge pull request #2985 from caseywebdev/generate-id

Re #2976 Allow `id` values to be generated from a function given attrs
#2985 -- use 'change-id' as the event name
Change the reference to rails in the 'sync' docs to reflect Rails 4
Merge pull request #3037 from rsofaer/update-docs-rails-4

Change the reference to rails in the 'sync' docs to reflect Rails 4
Update collection docs on underscore methods.
Merge pull request #3040 from braddunbar/underscore-methods

Update collection docs on underscore methods.
Fix #3015 - History#stop cleans up iframe.
Merge pull request #3041 from braddunbar/iframe-cleanup

Fix #3015 - History#stop cleans up iframe.