Switched to new style gradle Android application build process

--HG--
rename : android-project/jni/src/Android.mk => android-project/app/jni/src/Android.mk
rename : android-project/src/org/libsdl/app/SDL.java => android-project/app/src/main/java/org/libsdl/app/SDL.java
rename : android-project/src/org/libsdl/app/SDLAudioManager.java => android-project/app/src/main/java/org/libsdl/app/SDLAudioManager.java
rename : android-project/src/org/libsdl/app/SDLControllerManager.java => android-project/app/src/main/java/org/libsdl/app/SDLControllerManager.java

android-project/app/build.gradle

@@ -0,0 +1,35 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 25
+    buildToolsVersion "25.0.1"
+    defaultConfig {
+        applicationId "org.libsdl.app"
+        minSdkVersion 10
+        targetSdkVersion 16
+        versionCode 1
+        versionName "1.0"
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+    sourceSets.main {
+        jniLibs.srcDir 'libs'
+        jni.srcDirs = [] //disable automatic ndk-build call
+    }
+    lintOptions {
+        abortOnError false
+    }
+}
+
+dependencies {
+    compile fileTree(dir: 'libs', include: ['*.jar'])
+    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
+        exclude group: 'com.android.support', module: 'support-annotations'
+    })
+    testCompile 'junit:junit:4.12'
+}