Implement tuple.__add__, dict.__contains__ and builtin id() function

The __contains__ method crashes the runtime when using the 'dict' type directly

eg.  
1 in dict()  # fails deep down in stl

Also for id() I took the cpython approach by casting the address of the Box* to i64.  I noticed thats an llvm type, is that correct?
 
ok I fixed the bug :)  could we combine this file into dict.py?