Adding Support for extra Jetpack features

I added the following new features:

* Add support for Jetpack Omnisearch -
https://www.evernote.com/shard/s1/sh/9255d08a-e22f-4f8d-a923-49f99dbd6fc
5/42d7c8c439fb2400de78fa9690ff621e
* Improve basic copy for Jetpack Related Posts, instead of Related, it
now will say Similar Testimonials
* Added support for Jetpack Publicize and Markdown Editor support
Fix for Jetpack Related Posts Filter