generate code by ruby
Add rake task
Update xtend version.
Merge branch 'master' into block_editor

Conflicts:
	rakefile.rb
	src/main/java/net/unicoen/node/UniBinOp.java
	src/main/java/net/unicoen/node/UniIf.java
	src/main/java/net/unicoen/node/UniMethodCall.java
	src/main/java/net/unicoen/node/UniWhile.java
	src/main/java/net/unicoen/node_helper/Builder.java
	src/main/ruby/dsl.rb
	src/main/ruby/nodes.rb
	src/main/ruby/writer.rb
	src/test/java/net/unicoen/interpreter/EngineTest.java