Every defcustom should specify its type

Every defcustom should specify its type

* apropos.el (apropos-match-face):
* calculator.el (calculator-displayer):
* dabbrev.el (dabbrev-search-these-buffers-only):
* face-remap.el (buffer-face-mode-face):
* simple.el (yank-handled-properties):
* emacs-lisp/testcover.el (testcover-potentially-1value-functions):
* mail/footnote.el (footnote-mode-line-string, footnote-prefix):
* mail/hashcash.el (hashcash-accept-resources, hashcash-program)
(hashcash-double-spend-database):
* progmodes/ruby-mode.el (ruby-deep-indent-paren)
(ruby-deep-indent-paren-style):
* textmodes/flyspell.el (flyspell-auto-correct-binding):
* textmodes/rst.el (rst-toc-indent, rst-toc-insert-style)
(rst-toc-insert-number-separator, rst-toc-insert-max-level):
* vc/pcvs-defs.el (cvs-minor-mode-prefix):
* erc/erc-log.el (erc-log-file-coding-system):
* gnus/gnus-sieve.el (gnus-sieve-select-method):
* gnus/gravatar.el (gravatar-automatic-caching, gravatar-cache-ttl)
(gravatar-rating, gravatar-size):
* gnus/message.el (message-minibuffer-local-map):
* gnus/sieve-manage.el (sieve-manage-authenticators)
(sieve-manage-authenticator-alist):
Specify custom types.

* mail/hashcash.el (hashcash-program): Rename from hashcash-path.
Update callers.