Problem with csound_loader.js on Android

[Michael Gogins]

There are several versions of this utility... too many. The problem is here:

/**
 * There is an issue on Android in that csound may be undefined when the page is 
 * first rendered, and be defined only when the user plays the piece.
 */
var load_csound = async function(csound_message_callback_) {
    let operating_system = get_operating_system();
    if (operating_system === "Android" && typeof csound === 'undefined') {
        csound_message_callback("Operating system is Android, but Csound is not yet defined.\n");
        // On Android, Csound uses only stdout for messages; this becomes 
        // console.log, so we assign our "csound message callback" to 
        // console.log.
        return;
    }

I've made a variant, csoundloader.js, that omits this case, and should just proceed to load the WebAssembly build of Csound.