[ArrowHeads] Rename Functions arrowHead...

[discoleo]

ArrowHead Functions

• rename the functions to "arrowHead...";
• the name reflects that the functions create only arrow-heads;

  
  ### Functions to Generate ArrowHeads
  # (x, y) = tip of the ArrowHead;

Simple ArrowHead: --->

arrowHeadSimple = function(...) {...}

Diamond ArrowHead: ---<>

arrowHeadDiamond = function(...) {...}

...

[DarianFlorianVoda]

Done!