Setting DEBUG changed the cmake build type ("release" vs "debug"), which
had a bunch of undocumented and surprising consequences:
- changing CFLAGS/LDFLAGS etc, potentially to values unsupported on
OpenBSD, instead of just using what the user passed in DEBUG
- PLIST changes which break packaging when using PLIST_DB (default)
Leave DEBUG alone and introduce MODCMAKE_DEBUG as a documented feature
instead, as proposed by various folks. Reluctant ok landry@ (thanks!)
d1565529a6