Resolve "Make Parser slightly more noob-friendly"

Closes #2084 (closed)

The pattern for this implementation is well isolated, it only adds on top of the current parser implementation. For every parent element that has COMMA used in one of his children, add a recursive parser entry that ends in COMMA. It usually looks like this:

element: element
       | element COMMA element_param
       | element COMMA  // <-- the added line
       ;