configure, Makefile: Allow runtime to be overridden.

Makefile

@@ -52,7 +52,8 @@ util/%.so:
 	$(MAKE) install -C util-src
 
 %.install: %
-	sed "s|^CFG_SOURCEDIR=.*;$$|CFG_SOURCEDIR='$(INSTALLEDSOURCE)';|; \
+	sed "1s/\blua\b/$(RUNWITH)/; \
+		s|^CFG_SOURCEDIR=.*;$$|CFG_SOURCEDIR='$(INSTALLEDSOURCE)';|; \
 		s|^CFG_CONFIGDIR=.*;$$|CFG_CONFIGDIR='$(INSTALLEDCONFIG)';|; \
 		s|^CFG_DATADIR=.*;$$|CFG_DATADIR='$(INSTALLEDDATA)';|; \
 		s|^CFG_PLUGINDIR=.*;$$|CFG_PLUGINDIR='$(INSTALLEDMODULES)/';|;" < $^ > $@

configure

@@ -16,6 +16,7 @@ OPENSSL_LIB=crypto
 CC=gcc
 CXX=g++
 LD=gcc
+RUNWITH=lua
 
 CFLAGS="-fPIC -Wall"
 LDFLAGS="-shared"
@@ -171,6 +172,9 @@ do
    --linker=*)
       LD="$value"
       ;;
+   --runwith=*)
+      RUNWITH="$value"
+      ;;
    *)
       echo "Error: Unknown flag: $1"
       exit 1
@@ -341,6 +345,7 @@ LDFLAGS=$LDFLAGS
 CC=$CC
 CXX=$CXX
 LD=$LD
+RUNWITH=$RUNWITH
 
 EOF