BUILD: only set -g and -O options if explicitly requested.
BUILD: only set -g and -O options if explicitly requested.

 compiler debug & optimization flags are only set with either
  --enable-debug or --enable-coverage.
 This prevents defaults and environmental flags from
 been overridden.

Signed-off-by: Angus Salkeld <86b65304d27d8de73dd7d624c33df7e088f8d94b@redhat.com>

kgaillot/libqb,ClusterLabs/libqb,gao-yan/libqb,kgaillot/libqb,ClusterLabs/libqb,rubenk/libqb,davidvossel/libqb,kgaillot/libqb,ClusterLabs/libqb,gao-yan/libqb,davidvossel/libqb,rubenk/libqb