Support Sphinx builds compiled with --enable-id64

Sphinx 2.2.1 and above default to 64-bit document ids, and earlier
versions shipped a compile-time configuration flag to enable them.
Create the SphinxSE table with a "BIGINT" id column, which works for
both 64-bit and 32-bit document ids.
Merge branch '4.2/64bit-sphinx' into 4.2-trunk