Added heads up about computed properties to  'marking a model as complete-incomplete' page.

When a person reads this for the first time, he is left wondering why this function calls `property`. Even if there's a resource link in the bottom, it would nice to give a small heads up of whats going on up there.
Swap true result for false on template boolean check

I'm just getting started with Ember, but my results differed from the docs here. Is this right?
Fix integration testing docs on keyEvent

The function is `keyEvent`, not `keyDown`.
https://github.com/emberjs/ember.js/blob/master/packages/ember-testing/lib/helpers.js#L49
Show download button on Canary Channel.
Merge pull request #864 from benmoss/master

Fix integration testing docs on keyEvent
Merge pull request #852 from steverob/patch-1

Added heads up about computed properties to  'marking a model as complet...
Update marking-a-model-as-complete-incomplete.md
Merge pull request #878 from rjackson/show_download_on_canary

Show download button on Canary Channel.
Merge pull request #855 from appleYaks/patch-1

Swap true result for false on template boolean check
typo in writing helpers
Merge pull request #879 from twokul/master

typo in writing helpers
autolink in API docs
Merge pull request #880 from goshakkk/autolink-api-docs

Autolink in API docs