* src/commands.c (cmd_chargecard): Write a journal record for
subscriptions.
* src/journal.c (jrnl_store_charge_record): New arg RECUR.  Change
callers.  Write subscription record.
* src/jrnl-fields.h (JRNL_FIELD_RECUR): New.
(NO_OF_JRNL_FIELDS): Increment.
* src/payproc-stat.c: Extend stat format.
(one_line): Support subscription records.
(read_stat_line): Ditto.
(postprocess_statrecords): Ditto.
(print_output): Ditto.