Require url when compiling. Call

Require url when compiling.  Call
mac-process-deferred-apple-events after loading init files.
(mac-apple-event-map): New defvar.  Define event handlers in it.
(core-event, internet-event): New Apple event class symbols.
(open-application, reopen-application, open-documents)
(print-documents, open-contents, quit-application)
(application-died, show-preferences, autosave-now, get-url): New
Apple event ID symbols.
(about): New HICommand ID symbol.
(mac-event-spec, mac-event-ae): New macros.
(mac-ae-parameter, mac-ae-list, mac-bytes-to-integer)
(mac-ae-selection-range, mac-ae-text-for-search)
(mac-ae-open-documents, mac-ae-text, mac-ae-get-url): New functions.
(mac-application-menu-map): Remove keymap.  Handlers for HICommand
and Services menu events are now defined in mac-apple-event-map.
(mac-drag-n-drop): Remove selection range handling.