This adds a command queue to the PC speaker emulator for PWM-style sounds that
need timing of less than a millisecond. The play method only supports
milliseconds and requires real time control, which is difficult to achieve with
microsecond timings.
The new playQueue method allows you to queue up playback instructions with
microsecond timing, which are executed when audio samples need to be generated.
As discussed on the mailing list we should use title capitalization
only for push buttons and tabs and use sentence capitalization for
everything else.
