Reposition some code so defined before used.

Reposition some code so defined before used.
(displayed-month, displayed-year): Define for compiler.
(calendar-hebrew-month-name-array-common-year)
(calendar-hebrew-month-name-array-leap-year): Add doc strings.
(list-hebrew-diary-entries): Adapt for new behaviours of
`calendar-day-name' and `add-to-diary-list' functions.
(mark-hebrew-diary-entries): Adapt for new behaviours of
`diary-name-pattern' and `calendar-make-alist' functions.