Improve the custom type of some user options.

Improve the custom type of some user options.

* lisp/desktop.el (desktop-minor-mode-table):
* lisp/man.el (Man-frame-parameters):
* lisp/midnight.el (midnight-delay):
* lisp/speedbar.el (speedbar-select-frame-method):
* lisp/tooltip.el (tooltip-frame-parameters):
* lisp/tree-widget.el (tree-widget-space-width):
* lisp/type-break.el (type-break-keystroke-threshold):
* lisp/woman.el (woman-imenu-generic-expression):
* lisp/cedet/ede.el (ede-debug-program-function):
* lisp/cedet/ede/project-am.el (project-am-debug-target-function):
* lisp/emulation/viper-keym.el (viper-toggle-key):
* lisp/erc/erc-networks.el (erc-server-alist):
* lisp/gnus/message.el (message-deletable-headers, message-signature):
* lisp/mail/mailalias.el (mail-directory-stream):
* lisp/play/tetris.el (tetris-x-colors):
* lisp/progmodes/gud.el (gud-tooltip-modes): Improve custom type.