Patch updated for addressing Ezio's and Matthew's comments. MAXREPEAT now defined in the C code. It lowered to 2G on 32-bit platform to fit repetition numbers into Py_ssize_t. The condition for raising of an exception now more complex: if the repetition number overflows Py_ssize_t it means the same as an infinity bound and in this case an exception is not raised (i.e. it never raised on 32-bit platform). Tests added.