Converted ShatteredPD to Build from Gradle

Major Changes:
- Shattered now builds effortlessly either from gradle CLI or android studio
- Much better dependency management through gradle (although it's not really used atm)
- Separate PD-classes repo is now SPD-classes module within main repo

SPD-classes/build.gradle

@@ -0,0 +1,6 @@
+apply plugin: 'com.android.library'
+
+android {
+    compileSdkVersion 23
+    buildToolsVersion "24.0.0"
+}