(calendar-mayan-string-from-long-count): Rename

(calendar-mayan-string-from-long-count): Rename
calendar-string-to-mayan-long-count.  Update callers.
(calendar-mayan-print-date): Rename calendar-print-mayan-date.
Update callers, keep old name as alias.
(calendar-mayan-read-haab-date): Rename calendar-read-mayan-haab-date.
Update callers.
(calendar-mayan-read-tzolkin-date): Rename calendar-read-mayan-tzolkin-date.
Update callers.
(calendar-mayan-next-haab-date): Rename calendar-next-haab-date.
Keep old name as alias.
(calendar-mayan-previous-haab-date): Rename calendar-previous-haab-date.
Keep old name as alias.
(calendar-mayan-next-tzolkin-date): Rename calendar-next-tzolkin-date.
Keep old name as alias.
(calendar-mayan-previous-tzolkin-date): Rename calendar-previous-tzolkin-date.
Keep old name as alias.
(calendar-mayan-next-round-date): Rename calendar-next-calendar-round-date.
Keep old name as alias.
(calendar-mayan-previous-round-date): Rename
calendar-previous-calendar-round-date.  Keep old name as alias.
(calendar-mayan-long-count-to-absolute): Rename
calendar-absolute-from-mayan-long-count.  Keep old name as alias.
(calendar-mayan-goto-long-count-date): Rename
calendar-goto-mayan-long-count-date.  Keep old name as alias.