Refactor of Exceptions
Centralizing the definition of all exceptions in Cduce_core in a single module lang/lib/cduce_error.ml, packed as the new type error_t together with the location where the exception occurred.
Centralizing the definition of all exceptions in Cduce_core in a single module lang/lib/cduce_error.ml, packed as the new type error_t together with the location where the exception occurred.