Bump version 0.6.1

- Added getGroupIds dbus command
- Use "NativePRNG" pseudo random number generator, if available
- Switch default data path:
  $XDG_DATA_HOME/signal-cli ($HOME/.local/share/signal-cli)
  Existing data paths will continue to work (used as fallback)

build.gradle

@@ -7,7 +7,7 @@ targetCompatibility = JavaVersion.VERSION_1_7
 
 mainClassName = 'org.asamk.signal.Main'
 
-version = '0.6.0'
+version = '0.6.1'
 
 compileJava.options.encoding = 'UTF-8'