Add commonly used include headers

apps/app_adsiprog.c

apps/app_agi.c

apps/app_db.c

apps/app_festival.c

apps/app_macro.c

apps/app_parkandannounce.c

apps/app_softhangup.c

apps/app_striplsd.c

apps/app_substring.c

apps/app_waitforring.c

cdr/cdr_csv.c

cdr/cdr_mysql.c

channels/iax2-parser.c

dsp.c

file.c

formats/format_jpeg.c

pbx/pbx_config.c

pbx/pbx_gtkconsole.c

res/res_crypto.c

say.c