Store here migration scripts, named
-<nnn>-up-any-text.sql
-with contiguous indices starting with 001
+<nnn>-up-<any-text>.sql
+ handled as a sql script to be run against planetlab5, or
+<nnn>-up-<any-text>.sh
+ which is assumed to be a shell script and is run as is
+
+Another assumption is that
+ * nnn-up- script will set subversion number to <nnn>
+ * nnn-down script will set subversion number to <nnn>-1
+
+===
+See the migration script in plc.d/db for how this is used
+===