malloc/realloc type functions, as well as renaming one variable called 'new'
in tokensizer.c. Still lots more to be done, going to be checking in one
chunk at a time or the patch will be massively huge. Still compiles ok with
gcc.

This was the result of inconsistent use of PyMem_* and PyObject_* allocators.
By changing to use PyObject_* allocator almost everywhere, this removes
the inconsistency.

(reviewed by Neal Norwitz)

This should match the situation in the 1.6b1 tree.

Work around intrcheck.c's desire to pass 'PyErr_CheckSignals' to
'Py_AddPendingCall' by providing a (static) wrapper function that has the
right number of arguments.