This module implements the existing smart matching algorithm from perl 5.14,
as a module. It has a pure perl implementation of the algorithm (which can be
requested by setting $smartmatch::engine::core::USE_PP to a true value before
"use"-ing this engine), but by default it uses a C implementation which should
be identical to the algorithm in 5.14 - this module uses some new compiler
hooks to turn calls to the engine's "match" function into a custom op-code,
which is implemented by a copy of the smart match code from perl 5.14.