FPII-2070: FP Updater: rewrite XML parser

Isolate and rewrite the XML parser.
diff --git a/build.gradle b/build.gradle
index 296ab9b..f04b8cb 100644
--- a/build.gradle
+++ b/build.gradle
@@ -7,7 +7,7 @@
         maven { url 'http://download.crashlytics.com/maven' }
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:1.3.0'
+        classpath 'com.android.tools.build:gradle:2.1.2'
         classpath 'com.crashlytics.tools.gradle:crashlytics-gradle:1.+'
     }
 }
@@ -17,63 +17,3 @@
         jcenter()
     }
 }
-
-// Module level gradle declarations
-
-apply plugin: 'com.android.application'
-
-apply plugin: 'crashlytics'
-
-repositories {
-    maven { url 'http://download.crashlytics.com/maven' }
-}
-
-android {
-    compileSdkVersion 21
-    buildToolsVersion "21.1.2"
-
-    defaultConfig {
-        applicationId "com.fairphone.updater"
-        minSdkVersion 17
-        targetSdkVersion 21
-    }
-
-    buildTypes {
-        release {
-            minifyEnabled true
-            shrinkResources true
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
-        }
-    }
-
-    sourceSets {
-        main {
-            manifest.srcFile 'AndroidManifest.xml'
-            java.srcDirs = ['src']
-            resources.srcDirs = ['src']
-            aidl.srcDirs = ['src']
-            renderscript.srcDirs = ['src']
-            res.srcDirs = ['res']
-            assets.srcDirs = ['assets']
-        }
-
-        // Move the tests to tests/java, tests/res, etc...
-        instrumentTest.setRoot('tests')
-        androidTest.setRoot('tests')
-        
-        // Move the build types to build-types/<type>
-        // For instance, build-types/debug/java, build-types/debug/AndroidManifest.xml, ...
-        // This moves them out of them default location under src/<type>/... which would
-        // conflict with src/ being used by the main source set.
-        // Adding new build types or product flavors should be accompanied
-        // by a similar customization.
-        debug.setRoot('build-types/debug')
-        release.setRoot('build-types/release')
-    }
-}
-
-dependencies {
-    compile 'com.android.support:support-v4:21.0.+'
-    compile 'com.crashlytics.android:crashlytics:1.+'
-    compile files('libs/RootTools-3.3.jar')
-}