update gitignore

Author: lecion

.gitignore

@@ -1,6 +1,39 @@
-.gradle
-/local.properties
-/.idea/workspace.xml
-/.idea/libraries
+# Built application files
+/*/build/
+
+build/
+ 
+# Crashlytics configuations
+com_crashlytics_export_strings.xml
+ 
+# Local configuration file (sdk path, etc)
+local.properties
+ 
+# Gradle generated files
+.gradle/
+ 
+# Signing files
+.signing/
+ 
+# User-specific configurations
+.idea/libraries/
+.idea/workspace.xml
+.idea/tasks.xml
+.idea/.name
+.idea/compiler.xml
+.idea/copyright/profiles_settings.xml
+.idea/encodings.xml
+.idea/misc.xml
+.idea/modules.xml
+.idea/scopes/scope_settings.xml
+.idea/vcs.xml
+*.iml
+ 
+# OS-specific files
 .DS_Store
-/build
+.DS_Store?
+._*
+.Spotlight-V100
+.Trashes
+ehthumbs.db
+Thumbs.db