Prepare Howler Sound Manager for support a multiple sound sources

[ViktorVovk]

Functionality that supports multiple audio resources can be very useful, as we often use different types of audio assets in our projects—for example, ogg and mp3 files that we get after packaging. However, different browsers support different formats. Google Chrome supports the ogg format, but Safari does not; instead, Safari supports mp3. In HTML, we have support for multiple sources for the element. Howl, which is used in Sound Manager, also supports passing the src parameter as an array of resources and checks for support of the required resource.