Added microphone sound input

Adds microphone sound input support (the blocks <loud?> and (loudness) ). From my experiments with some projects, it works almost as well as the Flash player, but has a slight delay (I would guess quarter of a second delay for my tests). This uses "navigator.getUserMedia" for the microphone buffer stream, which is easy, but only a select few browsers fully support this. The following are:

    ~ Mozilla FireFox v32
    ~ Google Chrome v37
    ~ FireFox OS
    ~ Mozilla FireFox for Android (latest release)

Now, I believe that this is a W3 specification, so eventually most of the major browsers should support it.