[TIMOB-2850] Android: Yahoo module yql() calls fail if Ti.Network not used anywhere else in app

Failcase app.js:

Titanium.UI.setBackgroundColor('#000');
Ti.Yahoo.yql('select * from flickr.photos.search where text="Cat" limit 10', function(e) { });

Run that and it results in "Cannot call method 'createHTTPClient' of undefined" error.

If you modify it to look like this...

Titanium.UI.setBackgroundColor('#000');
Ti.Network.creatHTTPClient(); // DUMMY
Ti.Yahoo.yql('select * from flickr.photos.search where text="Cat" limit 10', function(e) { });

... it will work without error. I presume this is because our module detection code will see that Ti.Network.createHTTPClient and then include the titanium-network module in the APK. It's required for our yahoo module because the yql stuff works by loading and eval'ing a special Javascript file, yahoo.js.