Update gitignore.

Author: ashishkrishnan

.gitignore

@@ -1,9 +1,43 @@
+# Built application files
+*.apk
+*.ap_
+
+# Files for the Dalvik VM
+*.dex
+
+# Java class files
+*.class
+
+# Generated files
+bin/
+gen/
+out/
+build/
+
+# Gradle files
+.gradle/
+build/
+
+# Local configuration file (sdk path, etc)
+local.properties
+
+# Proguard folder generated by Eclipse
+proguard/
+
+# Log Files
+*.log
+
+# Android Studio stuff
+.idea/
+.navigation/
+captures/
+reports/
 *.iml
-.gradle
-/local.properties
-/.idea/workspace.xml
-/.idea/libraries
+
+### Android Patch ###
+gen-external-apklibs
+
+# OS specific ignores
 .DS_Store
-/build
-/captures
-.externalNativeBuild
+*~
+*.swp