Style changes. Error Handling. Bug fix. Logging silencer.

The style changes are to match Google style guidelines (this is just to give the file some consistency). I've included the jshint and jscs files, so future contributors can stick to the same styles with editor linters.

I've added error handling to cater for output changes after the camera has been initialised (Originally the files weren't being created).

I found a bug where this.watcher was being referenced when it needed to be self.watcher.

I've added an option specific to the Raspicam lib 'silent' this just makes the logging die in the background.

I've also added the ability to catch when the raspistill command isn't found (i.e. run on something other than a pi)