Add database management with SQLAlchemy

Add management of the pvcprov database with SQLAlchemy, to allow
seamless management of the database. Add automatic tasks to the postinst
of the API to execute these migrations.

api-daemon/pvc-api-db-init

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# Initialize the PVC database and migrations for future upgrades
+# Part of the Parallel Virtual Cluster (PVC) system
+
+export PVC_CONFIG_FILE="/etc/pvc/pvcapid.yaml"
+
+if [[ ! -f ${PVC_CONFIG_FILE} ]]; then
+    echo "Create a configuration file at ${PVC_CONFIG_FILE} before initializing the database."
+    exit 1
+fi
+
+pushd /usr/share/pvc
+./pvcapid-manage.py db init
+./pvcapid-manage.py db migrate
+./pvcapid-manage.py db upgrade
+popd