Doxygen documentation update from oej (issue #5505)

acl.c

aescrypt.c

aeskey.c

alaw.c

app.c

apps/app_adsiprog.c

apps/app_alarmreceiver.c

apps/app_authenticate.c

apps/app_cdr.c

apps/app_chanisavail.c

apps/app_chanspy.c

apps/app_controlplayback.c

apps/app_curl.c

apps/app_cut.c

apps/app_datetime.c

apps/app_db.c

apps/app_dial.c

apps/app_dictate.c

apps/app_directed_pickup.c

apps/app_directory.c