New changes in this release:

• Changing some namespaces, making it more standard compatible
• Renaming debug data type class name: checknan -> debugtype
• Allowing lazy evaluation of debug data types. Only throwing an error if the uninitialised value is used in flow control statements.
• Improving performance of debug data types
• Adding countr_zero and countr_one functions
• CPU backend now runs asynchronously, similar to GPU backends.