Fix #561 doctests to work under Python 2 and 3; remove problematic doctest from type_slots_int_long_T287.pyx

This is cleaner and has consistancy with how we handle removed PyInt* stuff.

--HG--
extra : rebase_source : 19ae472e99657b62b6730af74254345cf38d62a4

Fix #566, where __getslice__ generates code that gives a confusing compiler error under Python 3.  (Now you get a Cython compiler warning and a direct error message.)  A modification of the patch for #215.

trac #561: fixed major performance bug in special functions (by not generating Python versions and letting PyType_Ready() do it instead; details are on the trac ticket)

temp_expression must free its temps as early as possible