Initial checkin of javadoc for testing.
First cut at apple docs per IOS-496
Added survey section.
Moved to engagement rating flow in docs.
Added guide for testing Rating Flow and Surveys.
Moved Xcode setup steps from readme to `project_setup.md`
Separate coccoapods documentation
Expanded Cocoapods example
Expanded project setup document.
Moved project setup docs to iOS repo.
Move the features and integration guides into the docs repo.
Merge branch 'master' of https://github.com/apptentive/apptentive-documentation-private
Add stub testing guide file.
Update features.md

Add first Message Center screenshot to Ratings Prompt images.
Update features.md

Use the "sorry" intro dialog screenshot instead of the default.
Update features.md

Forgot a word.
Moved integration and testing guide to iOS repo
Update features.md

Remove push notification implementation details. Link to integration guide for that.
Update features.md

Add references to screenshots for push stuff.
Update features.md

Update screenshot links to point to my repo for now.