Handle incorrect hash/search values in IE6.

In IE6, the hash/search value will not be correct when the hash
fragment contains '?'.
Add comment, remove anchors.
Collection docs: models is not optional if options is passed in
Merge pull request #3152 from braddunbar/ie6

Handle incorrect hash/search values in IE6.
Merge pull request #3265 from tomascasas/bb-col-doc-update

Collection docs: models is not optional if options is passed in
Send correct 'at' when firing 'add' event
Merge pull request #3039 from fastest963/master

Send correct 'at' when firing 'add' event