Fix Bug#3888:

Fix Bug#3888:
w32-vars.el (x-select-enable-clipboard): Doc fix.
term/pc-win.el (x-display-name, x-colors)
(x-select-enable-clipboard, x-select-text): Doc fix.
term/common-win.el (x-display-name, x-colors): Doc fix.
term/ns-win.el (x-select-text, x-setup-function-keys, x-colors)
(xw-defined-colors): Doc fix.
w32-fns.el (x-select-text, x-setup-function-keys)
(x-get-selection, x-set-selection): Doc fix.
term/x-win.el (x-select-text, x-setup-function-keys)
(x-select-enable-clipboard, xw-defined-colors): Doc fix.
select.el (x-set-selection): Doc fix.