Removing the deprecated functions that read from String. Fixing the get_string_literal
Adding reader of null reference. ToDo: Fix the identificator to read ONLY letters and _
Adding the capability to get_reference_literal of reading multiple references. Not working properly. Need to work more on this
Moving from openGEX_lexer to openDDL_lexer. And fixing problems with comments and whitespaces (it has to be sure that it's not the end of the file). Also fixing problem with braces in data_array_list. ToDo: Test if it works properly with more than one data array list