There is currently no way (as far as I can tell) to tell IMP to build
a debug (non-optimized) version. I propose replacing the "release"
configure option with a "build" option which can be one of
- "debug" which makes a non-optimized version of the library with
debugging symbols
- "release" which makes an optimized version of the library but with
runtime checks enabled
- "fast" (or some better name, perhaps "ndebug") which used NDEBUG to
disable runtime checks (and is optimized and doesn't have debugging
symbols).