Update Web APIs page for Crosswalk 5 and 6 releases

Added APIs:

* Responsive images (Crosswalk 5)
* Vibration (Crosswalk 5)
* Launch screen (Crosswalk 6)

Also marked all APIs which appear at a particular version with
the version number mentioned in the release notes (I updated the
SIMD version number to reflect this too).
Merge pull request #112 from crosswalk-project/update-web-apis-page

Update Web APIs page for Crosswalk 5 and 6 releases
Add link to embedding API tutorial
Make regen.php errors visible

On the live site, regen.php doesn't appear to be correctly updating
the wiki Pages/History pages for the site. However, I can't see
what's going on, because all the error messages are suppressed.

Capture any errors and present them in a non-threatening fashion
(sans stack trace) to the caller, so I can debug.
Try a more explicit git fetch command to update wiki
Move Cordova content from wiki to website