[ADD/WIP] Start adding a lmdb flag to configure

Start of my work to get out LMDB support. I want to make it optional, as
some environments just can't use LMDB(due to mapped RAM limits, or
places where mmap is unavailable (a rather cursed platform!)).

Next up: Start separating Db to allow multiple subimplementations
instead of being expressly for nested-dir JSON ops.

configure

@@ -24,10 +24,10 @@ SCRIPT_ARGS="--prefix=/usr/local --lib-name=Cytoplasm"
 # Set SSL flags depending on the platform.
 case "$(uname)" in
     OpenBSD)
-        SCRIPT_ARGS="${SCRIPT_ARGS} --with-libressl"
+        SCRIPT_ARGS="${SCRIPT_ARGS} --with-libressl --disable-lmdb"
         ;;
     *)
-        SCRIPT_ARGS="${SCRIPT_ARGS} --with-openssl"
+        SCRIPT_ARGS="${SCRIPT_ARGS} --with-openssl --disable-lmdb"
         ;;
 esac
 
@@ -80,6 +80,14 @@ for arg in $SCRIPT_ARGS; do
             TLS_IMPL=""
             TLS_LIBS=""
             ;;
+        --with-lmdb)
+            EDB_IMPL="EDB_LMDB"
+            EDB_LIBS="-llmdb"
+            ;;
+        --disable-lmdb)
+            EDB_IMPL=""
+            EDB_LIBS=""
+            ;;
         --prefix=*)
             PREFIX=$(echo "$arg" | cut -d '=' -f 2-)
             ;;
@@ -104,6 +112,11 @@ if [ -n "$TLS_IMPL" ]; then
     LIBS="${LIBS} ${TLS_LIBS}"
 fi
 
+if [ -n "$EDB_IMPL" ]; then
+    CFLAGS="${CFLAGS} -DEDB_IMPL=${EDB_IMPL}"
+    LIBS="${LIBS} ${EDB_LIBS}"
+fi
+
 CFLAGS="${CFLAGS} '-DLIB_NAME=\"${LIB_NAME}\"' ${DEBUG}"
 LDFLAGS="${LIBS} ${LDFLAGS}"