Multiple fixes

* PDO shell improvements: .query command, -r and --db on command
  line to read commands from file or preselect database.
* Updated build scripts and readme

.spark/build/update-version.sh

@@ -1,5 +1,13 @@
 #!/bin/bash
 
+if [ ! -d .git ]; then
+    if [ ! -f src/version ]; then
+        echo -e "<?php define(\"APP_VERSION\", \"unknown\");" > src/version
+        echo -e "* Version: \e[1munknown\e[0m"
+    fi
+    exit 0
+fi
+
 VERSION="$(git describe --tags)"
 
 if [ -z "$VERSION" ]; then