adding minimalistic setup and transformation to handle functions as data to enable naive function generation for Quickcheck_Narrowing

adding a simple datatype for representing functions in Quickcheck_Narrowing

extending code_int type more; adding narrowing instance for type int; added test case for int instance

translating bash output in quickcheck_narrowing to handle special characters; adding simple test cases

adding size as static argument in quickcheck_narrowing compilation

modernized specifications;

dropped unused structure aliases;