added testfiles for block reference

src/main/java/com/ardublock/ui/OpenblocksFrame.java

...om/ardublock/ui/listener/SimulatorHelpButtonListener.java

src/main/resources/com/ardublock/block/ardublock.properties

...ain/resources/com/ardublock/block/ardublock_de.properties

src/main/resources/com/ardublock/reference/loop.html

src/main/resources/com/ardublock/reference/loop.jpg

src/main/resources/com/ardublock/reference/loop.png

...in/resources/com/ardublock/reference/program_comment.html

...ain/resources/com/ardublock/reference/program_comment.png