Add YUI coverageOptions for Yeti.

 - Do not instrument files in Yeti.
 - Use ?filter=coverage query to trigger loading instrumented
   files in tests.

Allows for `yeti -c` to use these options without specifying
them on the command line.
[docs] Add mock data to JSONP Gallery example
[docs] Add mock data to JSONP GitHub example
Merge branch 'mock-jsonp-examples' into dev-master
Merge branch 'dev-master' into dev-3.x