Fix tests when the sqlite3 command line utility isn't installed.

We know the user already has to have python, so use its bindings.

t/flush-cache.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python
+
+import os, os.path, sqlite3, sys
+
+if "DO_BUILT" in os.environ:
+    sys.exit(0)
+
+print >>sys.stderr, "Flushing redo cache..."
+
+db_file = os.path.join(os.environ["REDO_BASE"], ".redo", "db.sqlite3")
+db_con = sqlite3.connect(db_file, timeout=5000)
+
+db_con.executescript("pragma synchronous = off;"
+                     "update Files set checked_runid=checked_runid-1, "
+                     "       changed_runid=changed_runid-1, "
+                     "       failed_runid=failed_runid-1;")
+
+db_con.commit()
+
+db_con.close()
+