Changes related to content-view definition

- updated  activation-key.clj's 'create' function to support content-view-definition
- updated changeset.clj's 'add-content' function to support content-view
- Added few more functions in content-view-definition.clj

Currently I'm facing issue with add-product function in content-view-definition.clj. Selenium is throwing exception while selecting the product. Also, I'm getting few errors in firebug too (logged bz 929141).