Generic Coco/R and CocoXml for multi-languages
CocoXml is inspired by Coco/R and modified from it. The new implemented Coco(in c) and CocoXml are combined into one binary. If the extension of the input is .atg, it is treated as a syntax of the original Coco. If the extension of the input is .xatg, it is treated as a syntax of CocoXml.