[orx-minim] Exit demo if no sound device can be opened

orx-jvm/orx-minim/src/demo/kotlin/DemoAdditive01.kt

@@ -18,6 +18,10 @@ fun main() {
             val minim = minim()
             val out = minim.lineOut
 
+            if (out == null) {
+                application.exit()
+            }
+
             // generates a random frequency value biased down
             fun randomFreq() = 20f + Random.nextFloat().pow(3) * 1000
 

orx-jvm/orx-minim/src/demo/kotlin/DemoFFT01.kt

@@ -16,7 +16,14 @@ fun main() {
 
         program {
             val minim = minim()
+            if (minim.lineOut == null) {
+                application.exit()
+            }
+
             val lineIn = minim.getLineIn(Minim.MONO, 2048, 48000f)
+            if (lineIn == null) {
+                application.exit()
+            }
             val fft = FFT(lineIn.bufferSize(), lineIn.sampleRate())
             fft.window(LanczosWindow())
             extend {

orx-jvm/orx-minim/src/demo/kotlin/DemoPlaySound01.kt

@@ -5,6 +5,10 @@ fun main() {
     application {
         program {
             val minim = minim()
+            if (minim.lineOut == null) {
+                application.exit()
+            }
+
             val player = minim.loadFile(
                 "demo-data/sounds/26777__junggle__btn402.mp3"
             )