Multiple fixes

* Implemented ScriptRunner with environment expansion and cleaner
  code.
* Added ApiClient plugin (com.noccy.apiclient)
* Renamed CHANGELOG.md to VERSIONS.md
* Shuffled buildtools
* Added first unittests

.spark/build/update-version.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+VERSION="$(git describe --tags)"
+
+if [ -z "$VERSION" ]; then
+    echo "Could not parse version from git"
+    exit 1
+fi
+
+echo -e "<?php define(\"APP_VERSION\", \"$VERSION\");" > src/version
+echo -e "* Version: \e[1m$VERSION\e[0m"
+