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

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+#Mon Dec 28 10:00:20 PST 2015
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.10-all.zip