Update docstrings and comments to use "init file" terminology.

* bookmark.el (bookmark-bmenu-toggle-filenames): Doc fixes.
* comint.el (comint-prompt-read-only):
* custom.el (defcustom):
* hi-lock.el (hi-lock-mode):
* ibuffer.el (ibuffer-formats):
* ielm.el (ielm-prompt-read-only):
* novice.el (disable-command):
* saveplace.el (toggle-save-place):
* speedbar.el (speedbar-supported-extension-expressions):
* startup.el (auto-save-list-file-prefix, init-file-user)
(after-init-hook, inhibit-startup-echo-area-message):
* strokes.el (strokes-help):
* time-stamp.el (time-stamp):
* calendar/calendar.el (calendar, diary-file):
* calendar/diary-lib.el (diary-mail-entries, diary)
(diary-list-entries-hook):
* calendar/holidays.el (holidays, calendar-holidays):
* calendar/lunar.el (lunar-phases):
* calendar/solar.el (sunrise-sunset):
* emulation/edt.el (edt-load-keys):
* emulation/viper.el (viper-mode):
* eshell/em-alias.el (eshell-command-aliases-list):
* eshell/esh-util.el (eshell-convert-numeric-arguments):
* international/ogonek.el (ogonek-information):
* net/tramp-cmds.el (tramp-bug):
* net/quickurl.el (quickurl-reread-hook-postfix):
* play/decipher.el (decipher-font-lock-keywords):
* progmodes/cc-styles.el (c-set-style):
* progmodes/idlw-shell.el (idlwave-shell-prompt-pattern):
* progmodes/inf-lisp.el (inferior-lisp-prompt):
* progmodes/octave-mod.el (octave-mode):
* progmodes/sql.el (sql-mode, sql-interactive-mode, sql-password):
* progmodes/verilog-mode.el (verilog-read-defines):
* textmodes/two-column.el (2C-mode): Likewise.