updated Blockref

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

...in/java/com/ardublock/ui/listener/HelpButtonListener.java

src/main/webapp/com/ardublock/reference/ArduBlockHelp.png

src/main/webapp/com/ardublock/reference/abs-beispiel-1.png

src/main/webapp/com/ardublock/reference/abs.html

...in/webapp/com/ardublock/reference/addition-beispiel-1.png

src/main/webapp/com/ardublock/reference/addition.html

src/main/webapp/com/ardublock/reference/and-beispiel-1.png

src/main/webapp/com/ardublock/reference/and.html

src/main/webapp/com/ardublock/reference/arduBlockHelp.png

src/main/webapp/com/ardublock/reference/arduBlockHelp2.png

src/main/webapp/com/ardublock/reference/code_comment.html

...ain/webapp/com/ardublock/reference/code_comment_head.html

...n/webapp/com/ardublock/reference/constrain-beispiel-1.png

src/main/webapp/com/ardublock/reference/constrain.html

src/main/webapp/com/ardublock/reference/delay-beispiel-1.png

src/main/webapp/com/ardublock/reference/delay.html

src/main/webapp/com/ardublock/reference/digital-high.html

src/main/webapp/com/ardublock/reference/digital-low.html

...in/webapp/com/ardublock/reference/division-beispiel-1.png