Fix hack in SoundFontAdapter.ts

[klesun]

var presets: IPreset[] = null;
var drumPreset: IDrumPreset = null;
$.getJSON(soundfontDirUrl + '/presets.json', (result) => presets = result);
$.getJSON(soundfontDirUrl + '/drumPreset.json', (result) => drumPreset = result);

As you may see, we are relying on fact nobody uses SoundFontAdapter first couple of seconds after page load.

But the nobody does use the adapter instantly on page load. The nobody's name is Handler.ts::handleHashChange().

Reproducing:

• Change setTimeout(play, 1000); to just play(); in Handler.ts
• Open this link: http://shmidusic.lv/entry/compose.html#songRelPath=opus51_vike.mid.js

[klesun]

The solution i need - in fetchSample() if info not loaded - request same fetchSample() call when info loaded and return null

[klesun]

2957e04..1ee1b93