flyd issue #120 switchLatest: stream subscribers called more than once

see https://github.com/paldepind/flyd/issues/120 var flyd, mapped, stream, switchLatest; flyd = require('flyd'); switchLatest = require('flyd/module/switchlatest'); stream = flyd.stream(3); mapped = switchLatest(stream.map(function(x) { return flyd.stream(x * 2); })); flyd.on((function(value) { return console.log('!!!! stream ended', value); }), stream.end); flyd.on((function(value) { return console.log('-----!!! mapped ended', value); }), mapped.end); flyd.on((function(value) { return console.log('\n# stream value', value); }), stream); flyd.on((function(value) { return console.log('---> mapped value', value); }), mapped); setTimeout(function() { return stream(4); }); stream(5); setTimeout(function() { stream(16); stream.end(true); return stream('bad'); });