Added Web Speech API
Misspelled name

As the [specification](http://www.w3.org/TR/page-visibility/) confirms, the right name is with the whitespace.
Update vibration.json

Added information for Chrome and Firefox for Android
Opera supports Opus codec starting with v 20
Added background-blend-mode
Merge pull request #451 from AurelioDeRosa/patch-4

Update vibration.json
Merge pull request #453 from cabanier/master

Added background-blend-mode
Merge pull request #446 from AurelioDeRosa/patch-2

Added Web Speech API
Merge pull request #448 from AurelioDeRosa/patch-3

Misspelled name
data update
data update
Merge pull request #452 from baloneysandwiches/master

Opera supports Opus codec starting with v 20
data update